Ok so in general, I find it so much better to take notes by pen and paper, even though I'm not slow typer. it just seems easier that way, and you can always add in points in the margins or anywhere. If you really don't like handwritten notes, you can always re-type them just to have a neat collection all together- but that's just a suggestion of course. and for diagrams for example.. it would take FOREVER to do it on a laptop during the lecture, and to draw it in your notes and add it to the rest later.. would just make your notes all over the place.
As for the advantages of a laptop, like others mentionned, it's better than a desktop computer simply because it's portable. You can take it to the library and work on any assigment or project by yourself or with a group whenever you want, but then again, one of your group members might have a laptop, and the libraries of course have computers.
Another point to consider however, is what if rez gets too loud for example, or you just want a change of setting, it's SO convenient to just pack your laptop and head to the library or a study room, as opposed to a desktop computer.
Personal preference- I would go with a laptop, but that's just my opinion