Go with the Thrill. The only flaw is the battery life, but as soon as Gingerbread is put into it via OTA update, this phone will have NO COMPETITION, right now the only phone that is close is the SGS2, but considering the Thrill is faster already with 2.2 vs. the SGS2 with 2.3, imagine how much faster it will be when 2.3 drops.
Both are great phones (I have both here if you have any questions) but I have to recommend the Atrix 2. It's got more RAM and it is running a newer version of Android 2.3.5 vs the Thrill's 2.2.2. Performance wise they both appear to be great.
Radio shack is selling both for FREE this week if you are eligible for an upgrade or can add a line.