On my recent UA TATL trip I was shocked how great UA catering was (I even made a comment on the UA board). Plus UA has fully flat seats on all TAL flight. Overall it is fairly competitive product. For now I managed to stick to Star and oneWorld flights (I just lost my EY Silver status).
Ew, I think there are better options than UA out there.
I have recently spread my J flying across many diff airlines too (both OW and *), but UA isn't on my wish list. Not sure what you get on TATL, but my recent SIN- ORD was 8 seats across in J. Never again.
Back OT though, I agree with the OP and his attitude. There are a lot of great options out there and it doesn't hurt to review which one fits your specific requirements best at the 'right' (not necessarily cheapest) price point. I personally try to stick to OW and *, but other than that anything goes that has a good product (not UA)...