my upgrade rate as a Gold on Delta before 2010 was significantly better than as a 1k on United starting in 2012......
That being said, I like the upgrade offers at checkin and at booking. I often just buy upgrades. And I like the international upgrade system a lot.

Hmm, not sure I am flying the same airline as you. I was 10/18 on eligible flights last year, as a silver! And Irrops were handled well as well, certainly better than my experience on American, where they just rolled me from gate to gate in Dallas swapping aircraft as they went, ending up with a 4 hour delay all in 20 and 40 minute increments.

well, yes, it depends on the routes of course. LGA-ORD or LGA-DEN is extremely though, as are a lot of flights out of Newark and SFO. But I'm sure there are easy routes. I do get upgrades often for United Express, but that doesn't really count, and so many flights that I take don't have a first class (compared to Delta for example, where many more flights do)
I have no experience with American. IRROPS has been ok for me recently with United.

On what routes?

MCO to/from hubs and YEG to/from hubs. None through SFO or IAD.

Not surprised since MCO is a primarily leisure destination (captain obvious here lol), and most likely chock full of kettles.

On a flight out of LAS on a Friday morning last fall I think even a silver would have been upgraded. The front had only a couple of seats occupied.

Actually, I did better in and out of YEG than in and out of MCO, but yes, probably not a bunch of politicos/business people on my routes.

I was Gold last year and was upgraded on probably a third of my flights. It's not as impossible as people would make it out to be. Also got an op up LHR-IAH supposedly due to status but who knows, I just considered it a Christmas miracle.

so many defense contractors now flying steerage into and out of MCO? I think not! ;)

On what aircrafts?

YEG actually surprises me. I had to go up a few times in 2013, when I was only gold and was never anywhere near an upgrade. I'm guessing you were flying "off" days/times?

I struggle to buy this. 5500 miles LAX to NRT and return another 5500 miles. To only get silver that means you've already gotten 33,000 miles. So pretty close to every trip to NRT you get upgraded? After 20 years of flying, the number of international op-ups (esp. LAX to NRT, where I got laughed at as a 1k asking if my systemwide cleared), numbers in the low double digits.

If so, yes, let's go to Vegas!

I actually failed IAD-MCO the last 2 times I tried. Same for IAD-TPA. These used to be "gimmes" even during peak travel times because they were all kettles.

Although as a defense contractor I've flown to MCO a few times for work, by and large, it's leisure-only. The problem is that UA is both aggressively pricing discounted F (great if you want to buy it, which I have been doing for transcons and midcons--MCO is a bit short for me to bother), and of course offering those kettles the true TODs. And yes, I've overheard the infamous "I paid $50 for F, and I'm going to drink $50 worth of booze!" line several times on the route...

CPUs are for all intents and purposes dead. You might score one on a RJ here or there, or a really off-peak leisure route, but UA has figured out how to make even a few TODs on an upgrade. It's the way they're playing the game now.

For the person that asked what kind of aircraft, not the slightest clue, really don't pay attention. I do recall that there were some wide bodies out of IAH to MCO that had a large number of empty business class seats.
As to days, it was usually either Thursday or Friday going north and almost always Monday morning coming south, so not really off days, I don't think. Toughest in/out of YEG were YEG-IAH and vice versa, presumably because of the oil traffic. If I recall correctly, in and out of Denver was pretty much a slam dunk on both segments with empty seats available regardless of cabin size.