Xeno,
Sorry about your DVT problems.
I too switched from Delta to AA almost exclusively because of Delta's doing away with the big planes to TUL. (and I don't even have problems with blood clots-just like to sit in F.) Prior to switching, I was Silver on Delta and Gold on AA with no real special effort on my part. Now, I am PLT on AA--definitely a big step up. You need to do a Gold or PLT challenge to get status on AA. They won't comp you anything otherwise, but even a PLT challenge isn't that hard. As previous poster stated, do it in July so it will be good till 2/08.