I use the original Eee Pad Transformer to take notes in class and it works great, I'm sure the Prime will be even better. I use DropBox + OfficeSuite for my notes, but I also just purchased MobileNoter since I use Microsoft OneNote all the time and work and want to try that as well.
SuperNote is great and free of course, Polaris Office is a big pain in my opinion, I used it for a couple of days and quickly started looking for something better (which wasn't difficult to find). The Transformer's keyboard, battery life, and low weight are outstanding and make it far better than anything else in my opinion. To me the only thing that comes close is a MacBook Air, which weighs the same and is much more powerful, but is more expensive, no detachable touch screen, etc...