I've used both. Not for uni since I haven't started uni yet but for college. I've also used a laptop bag. If I'm carrying a lot, I prefer the backpack. It was easier to move around with it and I could carry a lot more stuff without my shoulders aching. The tote bag and laptop bag always made my shoulder feel terrible by the end of the day.
For days when I have less to carry, I prefer the tote bag or laptop bag. They don't take up as much space and they're so convenient to take around.