I am not a frequent flier, certainly not by standards of this site. Some years I make Silver, some not. So I clearly have to focus my travel.

I live in San Antonio. So far, I've been able to concentrate on NW/CO/DL. When I was silver on NW a few years ago I usually got upgraded. In reading another thread on this forum, most posters said that UA and AA miles were the best to have. My boss, who is an AA million-miler, said he's never paid more than 25K for a ticket (we're talking domestic coach of course), while I often pay more than that on NW and especially DL.

Any thoughts on whether I'm better off being silver on NW (with upgrade privilages on CO as well) or AA? Have upgrade chances gone down enough in the past few years to make silver on NW not worthwhile, so that I should go for the AA miles?