i avoid UA like the plague.

i know it's always a "your experience may vary" situation, but my experiences on CO have always been excellent (except for CO express, but that's a whole other story) and UA have been terrible.

...so i stay my ... off UA flights and haven't had a problem since. and i'm sure some UA FF's have had reverse experiences. find what works for you (sounds like CO metal is it) and stick with it, that's my 2c.