Let me add my two cents about US vs. UA in terms of service. So I'm a US1 and have upgraded I think every mainline flight except about two over the past few years. Since the codeshare started, I have had the opportunity to fly UA in F about 3-4 times, both short and long haul. Last night I flew IAD-SEA in F, which is nearly the same as PHL-SEA in F, a trip I make almost every week. Here are the differences I noticed:
1) UA uses glassware instead of plastic cups.
2) UA uses real silverware -- except for the knife -- instead of plastic silverware.
3) UA provides nuts (not warmed) in a cup instead of a bag of cashews.
4) UA provides a tablecloth to cover the tray.
5) UA provides a menu instead of having the F/A read off the meal selections. (Some US F/As do ok with this, others have no idea until someone in the first row corrects them. Then going forward they're usually good to go.)
6) UA follows some crazy way of taking orders. As a US1, which did show on the seating chart, I was the last person to place my order in a near full B757 F cabin. It's unclear what order she did follow, though, as not everyone was an elite UA member in that cabin.
7) UA offered an ice cream sundae with after dinner drink selection. They actually used a cart like US does (or did) in Envoy (haven't flown Envoy in several years).
8) UA provided a meager salad; US does a much better job with this.
9) UA seems reluctant to hand out bottles of water; this is something US F/As do that I've grown quite used to and really prefer.
10) UA's cabin was cleaner but had the same issues as US does ... mainly normal wear and tear after years of use.
11) UA's meal service took about an hour longer than US's.
12) UA offers music and Channel 9 IFE.
13) UA offers headrests on the seats, yet UA seems to offer less legroom in bulkhead seats (especially when compared with the US Airbus fleet).
Now, with all of this being said ... here's the bottomline from my standpoint: UA puts the finishing touches on its F product (and from my experience its Y product as well). But, I still prefer US's product in the end. When I'm traveling for work, I honestly don't want all the fanfare of F class nor do I want the headache of Y class. I almost like US's rough around the edges style. The US F/As also have a more low key attitude, which is so much more relaxing when traveling for work. I kept feeling on edge last night, as the UA F/As clearly had a very rigid agenda as to how the F cabin was to be serviced. UA does a great job, yes, and many people want the finer touches of F class, but for as long as US sticks around I'd rather fly them on transcons. (This being said, I almost wonder if US should market the F cabin differently altogether ... but that's a whole different topic for a different day.)