Yes, suspension mountain bikes are quite comfortable. I used to scorn at them somewhat because I thought they are slow and inefficient (they are indeed slower) but I tried a friends and I could not believe how comfortable his bike was (but that one was very heavy) it was a new experience. My commute is already borderline for road/touring bike (poor roads) but if you are going on gravel, stone, mud, etc. it is worth considering. It will save the vibration you get on your commute from making you look like you have parkison desease when you get at destination.