I commute on road bikes. The roads are in good shape on my commute but hilly, so I don't want a heavy bike to lug up the hills. For the past 3 years I commuted mainly on a touring bike (Bob Jackson World Tour) but I have transitioned over to a sport touring bike (Salsa Casseroll) because it is lighter and nicer riding. I also ride my other road bikes (De Bernardi, Eddy Merckx) on nice days when I don't need to carry much gear. I recently bought another sport touring frame (Waterford RST-22), and I am swapping all of the components off my Jackson to build it up. Riding the Casseroll for 5 months convinced me that a full touring bike is overkill for my commute, which is about 22 miles roundtrip. Also, my commute distance is increasing to about 30 miles in October, making a lighter, faster bike even more important to me.