Thanks for all the feedback given, everyone. I have ridden both bikes and compared the speeds that I can achieve on both, and found that I am able to travel faster with my old bike (over the distance of five miles). The only reason I bought a mountain bike is because I like to ride some dirt trails nearby my residence, otherwise I would have gotten a road bike for all the city commuting that I do. Also, the cogs on the rear of the bikes are the same sizes. I'm going to miss the extra speed on the old bike, but many of you have advised against changing out the sprockets, and I don't have the tools necessary for removing the cranks. So I will just have to deal. Other than all that, I really dig my new bike!!!