Brands are really different, I found that regardless of what they call it, you have to test ride it, adjusted for you, to see if it fits. I have a 95 Zaskar Mt bike that fit me off the shelf like it was custom made, I still have it, it's my most valued possesion next to my dog. I've test ridden a lot of other high end Mt bikes, the shop guys asked me to try out some rides, and they just didn't fit. Brands are so different. It's just like buying clothes, you never know until you try on.
The thing with a Treck, you can trade it in or sell it off later, it's a popular brand. Ride it for a year, learn what's going on with a bike, and if it gives you trouble sell it off and you'll have a good understanding of what you want next. My first Mt bike was a Giant, and the top tube was too short, utter hell to ride at about six months once my posistion on it flattened out. But then the day I got on the GT I knew it was fate.
Then again, your new bike may be perfect. In a few months, get the fit checked after your posistion on it settles down. And even if the bike is great, you may fall in love with something else later, say that orange Orbea team frame, well, that's what I want. If you went to a good shop with a competant proffessional, the Treck'll probably be a good starter bike.

Lizzy

And Irulan is right- EAT SOMETHING!