I had the same decision 2 weeks ago. I wanted something faster then my mountain bike. So it was either a road bike or a hybrid. I went with a hybrid reason being I still want to go in back alleys and a light trail and not worry about flats. I got the 08 trek 7.3 fx.

So far, its been a dream to ride. Its worlds faster then my mountain bike and the gearing was much better. I was surprised how efficient it was. I had more energy and could ride longer compared to the mountain bike. I looked at the reviews of the 7.3 fx before I bought and had solid reviews.

I am another happy trek owner and will be considering a trek road bike in future for long distance cycling. As for commuting the trek 7.3 fx handles the job really well.