Regarding miles: If the merger goes through, United/US Airways have said that your new status will be determined by the combination of tier miles on both miles (25,000 on US Airways and 75,000 on United will earn you 1K; 125,000 on US Airways and 0 on United will earn you 1K). If the merger is approved by year's end, this will determine your 2002 status. If we still don't know, it's anyone guess how this thing will pan out...

Regarding service/enjoyment: Absolutely no question in my mind that US Airways is the winner, assuming you will fly via Charlotte or Philadelphia to get the A330 (I believe PIT-LGW is still a 767-200). The A330 is superior in every aspect from what I hear. I've flown Envoy Class in the 767, and I can say the service is extremely superior, and that isn't going to change on the A330. The A330's seat will have more recline and pitch than an unrecongfigured United Business plane. The entertainment system is a Sony Passport Interactive system which 100 times better than United. Basically there aren't cycles of movies on channels. Rather there are many, many movies loaded into the system, but no indiviudual tapes for you to deal with. You select one movie, and fast-forward, rewind, pause (to go the lav, etc.), and restart exactly where you left off.

If this flight will bring you over the 1K line for the year, I'd say only under that considerion go United (just in case your miles don't go through -- no merger), but if either this flight won't affect your 1K status OR you would be willing to make a quick mileage run at the end of the year when you see that your US miles won't transfer and you need a little boost to get to 1K, a highly, highly, suggest that you choose US Airways and enjoy Envoy Class while you still can.

Or, a summary:
US, US, US, US!!!!