I take mine to my A&P lab because my instructor talks really fast and doesn't spend much time on his slides. His lectures are literally under 20 minutes long on a normal day, haha. I do not take it to anything else, as I don't really like reading notes on the computer.
It depends. My A&P prof uses detailed PowerPoint slides and most students take their laptops and add notes to them instead of printing them out. I print them out because I like drawing arrows and pictures of stuff.
I took history from a prof who talked really fast and, since I can type faster than I can write, that helped a lot.
It just depends on the professor.
Oh, almost forgot, I did have one teacher who said if you wanted to use a laptop you had to sit in the front two rows of the class. Unfortunately most of the people who sat there from the beginning didn't use a laptop so I could never get a sit there to use mine. :/
I take mine to Anatomy b/c the prof posts her slides and it's easier to download and take notes on the powerpoint directly rather than to print it out, plus it's super light to carry. I'm only one of three or four in my class to bring one, but I do know others bring in kindles and whatnot.