I use a 7700 FX that I bought 3-4 years ago, and it's still works great (it's black with blue accents). When I was shopping around I looked at the lower end 7200 FX, but I decided to drop the money for higher end with the XT shifters and the nice Bontrager rims.
Frankly, I think the extra money was worth it. The Bontrager rims are fabulous and almost never come off of true -- plus they look cool. The XT shifters are slick except they need tweaking every 3-4 months. Mostly it's all very low maintainance and I've never had to replace any parts.
So if I were you I'd take a look at the higher level Treks too. Of course gear gets to be diminishing returns where idiots pay $500 for pedals just to save a couple ounces. However, I thought the 7700 FX was worth it.
As a bonus, Trek bikes are nice too if you live in a urban area because bike thieves typically ignore anything with Trek frames -- especially ones that look as bet up as mine does. Speaking of being a theif target, if you do live in an urban area, it's actually an advantage to let your new pretty paint job get beat up.