Not a particularly heavy one. Mostly word processing, web browsing, and pdfs, although I do suspect I'll be doing some work with keynote by the end of next semester. Any sort of gaming I've got a proper pc for. I know I've also developed a fondness for taking notes by hand on my surface pro 2 that I'm looking to replace, so I might opt for macbook + ipad pro if that's not too expensive a combination (although I imagine the 2018 ipad refresh will get me be just fine there).
At that point I think you're better off just getting an iPad. You have to modify how you do things to work on an iOS device (trying to have the same workflow as your PC is going to end badly) but power and good applications are not an issue on the platform (the iPads are way faster than the MacBooks.)