I completely echo the service thing. If they aren't bending over backwards to get your business, they aren't worth it. I have very much lucked out on my two recent purchases, and will definitely be frequenting both shops. I'd like to get a Surly Karate Monkey or Long Haul Trucker build up when I hit my goal, and I'll be having shop 2 do the build. They might be a little more expensive, but they keep bending over backwards for me. That, in my mind, you can't put a price tag on.
I have a Trek 7.3FX and am generally very pleased with it. However, I think the shop is full of idiots if they recommended you buy something that is the most expensive that you could afford. The 7.5 is nice and all, but if you are on a < $600 budget it isn't worth the step up over the 7.3. Now if you were talking the 7.6 or 7.7, then maybe, but not just going from .3 to .5.
My only gripe with my FX is the rear wheel, but that's getting remedied currently. I'll be without it for most of the week and back to the MTB, but oh well. When I get it back it'll be better than new with a hand-built rear wheel and a Brooks
.
That being said, I echo what others here say. Go with the shop that really wants to earn your business, and forget about the brands they carry. Cannondale makes good bikes, the Bad Boy line in particular are very sweet.
Good luck!