After having been assiduous about flying UA metal (or at least UA ticket) for years in my quest to hit PQD requirements for 1K, this year I'm not going to chase this. I won't make 1K (due to PQD requirements), but will make it to over 75K PQM. What this has done is to release me from chasing UA tickets (and UA metal as a frequent consequence). For domestic flights it doesn't make much difference, but given that most of my travel is international, this can make a big difference. Why? Because UA's service is often lousy (and getting worse), which makes a big difference on 8+ hour flights. These are the things that matter to me the most:
1. number of empty seats/load factor on flights
2. quality and quantity of food
3. seat comfort
4. privileges I get on UA due to my Plat or 1K status, depending on the year

And the following minor considerations:
5. Quality of service of flight attendants: this is admittedly a minor consideration
6. Quality of inflight entertainment

On #3 , with E+, UA is a clear winner. (Yes, I know most airlines now have a premium economy product, but that's not the comparison I want to make here.) However, increasingly E+ alone doesn't seem to be enough to keep me with UA metal when #1 and particularly #2 are bad, especially in comparison to some *A partners.

In general my overall recent experiences on AC, SAS, Swiss & LH tells me that they're not any better than UA. But it's been a while since I've flown partners like SQ & NH. And I've never flown others like TK, AV & CA (coach).

So the question is, which of the following airlines would you choose over UA, knowing full well that you won't get the equivalent of E+ on them?

Avianca
SQ
NH
CA
Copa
Asiana
Air New Zealand

I think it makes more sense to think about aircraft types than airlines.

For example, if I'm not worried about United miles at all, I would pick a A330 or A350 over a UA (or any) 10-abreast 777.

And if you aren't chasing UA RDMs or PQMs, there's no reason to limit your self to Star Alliance. In any case, discount economy on many Star Alliance partners earn little or no miles on United.

The load factor, quality of food and other soft products don't vary by aircraft type. Well, things like entertainment units, do. But E+ space doesn't vary as far as I can tell.

I have flown AC NH and SQ economy in the past few months and SQ was great for service, an amenity kit in E, wow, and the seat was good as I checked in early at the airport and got an emergency row with unlimited legroom. NH was also good I left decent space and service was great.

AC is actually not too bad too but again depends on aircraft, their 77W 10 across is just as brutal as UA 77W 10 across. I have not flown AC 787's yet but I have survived UA 789 service to / from SIN many times and it really was not too bad.

I think another factor you should consider is the loads, if you can get an empty seat beside you in E+ on UA, I would say that is your best bet. I have had this several times to / from Asia due to E+ costing a ton for non-elites, and it makes it a really pleasant flight.

E+ varies based on aircraft. You get a seat pitch of 37in on 752 or 34in on 777. Also seat width, you get 18.5in on 763 or 17.1in on 777.

But if you're metal agnostic, why not just pick based on price, schedule, and aircraft type.

Thanks for your feedback. I've flown CA in business. It wasn't great, but then when you're flying business there really isn't much to complain about either.

My recollection of SQ is that the food in E is so much better than even the best UA has served up. But your point about an empty seat in E+ is valid. The load factor on flights to SIN from LAX & SFO tend to be low and chances are high that you'll end up with an empty seat next to you. Even though 15-16 hours to SIN sounds like a nightmare, empty seats next to me have made the flights less uncomfortable. In contrast, I can't imagine flying EWR-DEL/BOM though. 15+ hours on a 777 flight that's very likely full, is not something I'd look forward to, especially when things like food and in-flight entertainment are also substandard.

For me, if only UA invested in providing better and more food, especially on the really long flights, and their FAs made even a basic attempt at listening to you before brushing you off, I'd not be looking for an alternative airline to fly on. Their E+ seating for the price of E (for elites) is perhaps the only thing that keeps me flying them.

I am embarrassed to admit I hadn't realized that seat dimensions in E+ varied. The width, in particular, does make a big difference on long flights. I've flown all these aircraft you've mentioned, and while I've felt more cramped in some of them compared to others, I always attributed that to how I felt that particular day or how much space my neighbor took.

I am going to second exactly what sincx said - it is aircraft specific. At this point, the seat width is as important, if not more inportant in my book, and a tape measure does not lie:The bottom line is that per seat, once the 19” standard aisles are taken out,
:-A380 (at 10x, lower deck) has 21.8”/seat (at 8x, upper deck) has 23.8"/seat
-777 (at 9x) has 21.3"/seat
-763 (at 7x) has 21.2”/seat
-A330/330neo (at 8x) has 20.8"/seat
- A350 (at 9x) has 20.3”/seat
-737/757 (at 6x) has 20”/seat

-787 (at 9x) has 19.8"/seat
-777 (at 10x, using 18” aisles as UA is, which is why they are so narrow) has 19.4”/seat

So ex-SFO (we get 772s and 787s ex-SFO) I am NOT going to fly UA in Y. period. Even with a 34" pitch, the super narrow seats are a non-starter . SQ flies either a A359 or a 773 (at 9x in Y) from SFO, and I would much rather take that with their standard 32" pitch than the narrow E+ seat on UA (and I can usually get an exit row). Ditto Asiana, which I actually recently took on the A359 in Y, which actually gives a 32-33" pitch (and has a E+ section) and the A380 is one of the best rides in Y in the upper deck in the sky.

ANA, however flies 10x 773s ex-SFO (they also have a 9x that is great), and since they started doing that, I have not flown them (except in J or PE), just not going to do it. but other than that one Aircraft, I would happily take ANA in Y over UA any day of the week.

CA is a crappy airline, and it has 10x on its 773, but if someone forced me to, I would probably prefer to fly on their A359 which has 32" pitch than on UA's 777 with 10 across seating in Y, even with the greater 34" pitch. Put another way, I would rather be on the A359 with 32" pitch than the UA 777 at 10x, even with a 34" pitch.

I have no experience on the rest of the airlines, but would not take NZ in Y, given that they have the 10x Y seating on the 773. I would however gladly take then in their PE product, which is one of the best around.

Bottom line is that outside of the 763s, which still have decent seat width, there is not a SINGLE UA long haul bird I would fly on in Y at this point, and that is just looking at the seat, not the crappy food, service, etc.

Spin88, I agree that seat width is more important than pitch for people of average or below average height. But, based on seatguru, seat widths are as follows on the aircrafts used by the following airlines to a sampling of destinations in Asia:

UA 777: 17"
UA 787: 17.3"
SQ 350: 18"
SQ 777: 19"
ANA 787: 17.3"
Asiana 350: 18"

For the sake of comparison:
LH 380: 18.2" (but seat pitch is 31")
TK 777: 18"

Going from a UA 77x to SQ 77x is a 2" difference, which is significant. But going from a UA 787 to SQ 350 (as in the respective airline's SFO-SIN nonstops) is only a 0.7" difference.

Seat guru and the airlines are selling a bunch of bunk. Just ignore those figures, they are NOT an accurate reflection of what the seat actually feels like. They involve funky efforts to measure just the width of the seat pan, and the response has been (by those trying to game the system with ultra tight configurations) to shrink the arm rests and/or expand the seat pan under the arm rest. The actual space is the middle of the arm rest to middle of the next armrest or the edge of the arm rest (for the aisle and window seats).

I simply took the available floor space, took off the aisle size (typically 19", but the new 10x 777s use 18" aisles, part of why they feel so cramped, because they are...) and then divided by the number of seats. The figures will be off slightly due to the slightly different curve of the sidewall of the plane, but they best reflect reality. Anyone who flies enough - and is of bigger frame - will tell you that the 787 e,g, is a tighter than the A330/763/ old 777 at 9x, and also tighter than a A359. Likewise, the A320 series, with 7" of width in the cabin, is more comfortable than the 737, something I notice on longer flights.

Empty middle solves 99% of the seat width problems IMO.

I agree.

While some posters focus on the minutiae of seat width, I find (a) pitch is more important, and (b) when someone's too big for the seat, it's rarely by an inch.

Specifically, the worst long-haul Y flight I've ever flown was OZ, on a 9-across 777 with no legroom. On the other hand, I've flown an ANA 787, in the exit row -- extremely narrow seats -- and it was fine due to the extra legroom. (To be fair, I had an empty middle seat, but that's somewhat less useful because the tray tables were in the armrests. It did matter at shoulder height, though). And, I had a terrible experience on ANA's famous knee-crusher 767s.

To answer the original poster's question, while noting that I haven't flown Y on each of these carriers, if I didn't care about pitch, I'd fly NZ, NH, or SQ over UA. AV and OZ are both in various amounts of financial trouble, and I've rarely heard good things about CM. And I would avoid CA for many reasons, including not wanting to connect in mainland China. I would also add BR to your list, keeping in mind that BR does now have some 10-across 777s.

On the specific four points:
1 - I'd expect load factors to be full on every carrier, unless I had some specific reason to think otherwise. For example, if I were flying SFO-SIN on UA during the winter, I'd know there was a good chance they'd have to block seats due to headwinds on the westbound trip.
2 - I have never had an appetizing meal in Y, on any carrier. (I've had plenty of bad meals in J, too, on multiple carriers). I tend to eat at the airport.
3 - I care about pitch, so UA wins, although I'd still avoid the 10-across 777 if at all possible. (Since the experience with Asiana that I mentioned, I've vowed never to fly overseas in Y unless it was an emergency; not everyone has that luxury, of course). If I couldn't avoid the 10-across 777, I'd look to see if I could purchase extra-legroom seats on another carrier. (Yes, the pitch is that important to me).
4 - You'll get *G treatment on any of the carriers that you mentioned, including club access and a larger baggage allowance. If you need 3 bags x 70 lbs, you need United metal, though.
5 - I have had horrible crews on UA and CA. I've had great great crews on UA, TG, SQ, and NH. I've had acceptable crews on UA, TG, NH, OZ, SQ, NZ, BR, etc. Mostly, I sleep.
6 - I bring my own and generally only use the IFE for the flight map. That said, this really varies by equipment type at least as much as carrier.