Apologies for the buzzwords, but I'm trying to weigh the most optimized method of of travelling from YYZ-SIN-YYZ in consideration of the following:

Upgrade-ability - I am AC*E and have 25 eupgrade credits. Route optimization to make best use of my credits for the round trip (ie most miles with my butt in J). My ticket will be in Y, but presumable T+ . Likelyhood of upgrades vs paid J vs SEs upgrading also needs to be considered

Comfortability - I understand Asian carriers have a better soft product in Y. How should I hedge my bet / allocate legs in Y assuming that at best, 25 credits will only get me part of one way in J. And with which carrier?

Thoughts and input are welcome

My preference is YYZ-NRT-YYZ and connecting with SQ from Narita. But I have also seen that lately the flight to PVG is easily upgradeable. For easy upgrades try to book Mon,Tue or Wed. Also on toureast I have found fares to SIN for about $1300 all in connecting in ICN,NRT and HKG(not easy to upgrade). Good Luck.

I would definitely avoid connecting through YVR as that'll obviously cut a couple of hours off your time in C and it will be harder to upgrade in the first place. I might actually go for connecting through PVG and taking SQ from there. It's much better than PEK (imo) and it gets you somewhat closer than NRT.

i usually do YYZ-NRT-SIN............. There is a fare where its

YYZ-NRT AC/L, V class depending on whats available
NRT-SIN SQ/K class

Now the problem is, with the service cutbacks between SIN-NRT and addition trips going to HND.....the layover @ NRT has been lengthened significantly

Also the NRT-SIN portion of SQ11/12....departs later now......

YYZ-HKG-SIN will get you the most miles in J and make the second leg in Y quite bearable at about only 3.5 hours on SQ vs. nearly 7 hours if you connect @ NRT. It's also quite alright upgrade wise if you fly on slower days. layover times are also quite alright with about 3 hours inbound and 5 hours outbound.

PVG and PEK are both a bit of a hassle to connect through so I'd avoid them if you are inexperienced.

AC codeshares with SQ on HKG-SIN but be forewarned that you may very well end up with a non-mileage earning fare on that leg. I also suggest pricing out UA on HKG-SIN separately as sometimes you can end up saving quite a bit of money vs the AC/SQ codeshare and also ensure you get miles for all segments.

BTW, you don't have enough credits to upgrade from cheap T+ for both AC flights unless you're crossing a threshold and have enough time between your departures for the credits to post.

Miles in J?? OP is upgrading from Y using Ecredits. And the OP does not need to book a codeshare flight to avoid the mileage earning confusion.

OP could avoid a codeshare via AC but then he/she'd risk getting stuck with a T ticket that could hinder upgrading. I'm just giving a heads up so no surprises in case OP books the codeshare and doesn't get the miles for the SQ portions. UA actually has fantastic fares ex-HKG bound for SIN but the flight times suck and you will not be able to get a BP at YYZ from AC although they will interline. You would then have to take the extra step of collecting the BP at UA's desk at HKG before heading to security/lounge.

And I was wording as OP did:

ok Payam I get the Message, lol.

haha just sayin' lahhh

but YYZ-HKG is hard to upgrade....unless OP is a SE Elite or buys into Latitude fare.....

also OP could technically choose UA as an option between HKG-SIN with some of the fares

I think we are complicating things for the OP, simple option, like I mentioned earlier, YYZ-NRT-SIN or via PVG. Easy to upgrade. One more thing, I also noticed that if buying a tkt on ac.com, they price BKK(from YYZ) cheaper than SIN, just something to think about.

They used to when they ran the UA 747s HKG-SIN. Now they run CO 737s with the same crappy timing but higher fares. You might still be able to find a deal, but I doubt we'll be seeing more of the HK$1600 r/t of yore.

You're right. I see the base fare has jumped about 50% now for a RT coming in at just about USD 300-350!

Oh well... I think I flew at least 5 RTs on those cheap fares this year despite the brutal timings. I just couldn't resist the super cheap fare, 100% SE bonus and almost guaranteed empty row to one's self in the 744.

why buy 2 tickets?

Some of the travel agent contract rates allow two airlines to be on the same ticket for one price.....

The AC Tango Plus + SQ/UA are all 100% mileage eligible... Last time I did this, it was about $1200ai

Yeah, they were perfect for just spending weekends on a whim in SIN. At least HX still charges decent fares.