Several of my classmates use iPads in class and they seem to like using them. I've always been a PC guy, and I take all of my notes for class on my computer. Like DrGator said, the lecture halls have power outlets now that allow you to use your laptop/iPad indefinitely. Carrying my 15" Dell laptop around hasn't been that big of a deal, since I don't really use textbooks anyway. All classes (except for Anatomy which requires the use of Netter's atlas) can be studied for using BRS, the class notes, and Wikipedia. So far it's worked out well for me.
Just a couple of things to consider:
1. I have yet to hear of a compatibility issue with regard to Macs, so if you want to purchase one, go for it. Personally, I think they are overpriced pieces of garbage, but hey, I'm just the class IT chair, what do I know.
2. Our class is about 60% take notes on computer, 40% use traditional paper notes. Just consider this when you think about how you best learn, and what kind of computer you would like to have.