I love my Rockhopper mountain bike in the commuter role. My only change would be the slimmer tires but I am not a speed junkie and am quite happy with my 10 to 12 MPH commute of 9 miles round trip. I also have a few curbs to jump as well as a shortcut off road so the MTB is a better choice on that route. I have $500 in it including a rack and trunk bag. I went that route to give me a duplicate of my issue police bike for personal use. Works great. I might put some fenders and skinny tires on it but for now it is a real winner.

I do have my eyes on a Specialized Allez entry road bike (about $600) to try my hand at that game. Might like it much better for the commuting role if I do the 5 mile route, road only.