The grass is definitely not greener at United.

I just flew:
SFO-IAH Continental First
IAH-CDG BusinessFirst
CDG-IAD United First
IAD-SFO United Business

I have to say that BusinessFirst wins hands-down, and that was on a 767-400, which is less than state-of-the-art.

Continental had warm, accommodating staff (especially the concierge in Houston), outstanding food, and a spotless airplane. True, the video was not on-demand, but the seat was comfortable enough. The crew were reasonably cheerful, and seemed to enjoy their jobs.

United First paled in comparison. Yes, there was more space. But that was it. The plane was dirty and worn. The crew were indifferent and sloppy. Their own bags and take out food were strewn across empty seats in first class. I'm pretty sure that the pre-arrival meal, risotto, was some sort of cat food. The food, cocktails, presentation were all pretty sad. And it seemed so arcane to use cassette tapes for entertainment on a small screen.

United mishandled my bag in Dulles, and it therefore took an hour and forty minutes to clear customs.

When I was re-accommodated, the gate agent in Dulles downgraded me from First to Business, apparently to be hostile and condescending. (I gave up and just wanted to go home.) Business was actually reasonably comfortable despite having a middle seat. The crew were much nicer on this flight, but the food was a no choice economy class-style meal.

It was a little experiment, and I'll be happy to back on Continental for future flights. Sure, Continental has its shortcomings, but they just reinforced my loyalty.