I am thinking back to when I was looking around for my first real bike. I went to a number of bike shops (three I think) and they all had the same general range. But the guy at the first shop I went to told me a lot of information about bikes in general and gave me a lot to think on. But, he took one look at me and said something along the lines "I'm not sure the 21 gears would be enough for you, try for at least 24 gears". Now I don't mind him considering my (over)weight to be a factor, in fact it is good, but why suggest it in terms of gearing? Especially since I know some of the clydes around here ride fixed gear or single speed.
In more information I think (from memory) that he was suggesting the Trek 4300 or 3900 over the 3700.
I am rather miffed at this. If no one can give me an answer I feel good that I didn't buy this bike off him.