I bought the Nexus 7 and have no regrets. It's portable enough to stick in a white coat pocket, and any larger would be too big to carry around with me. I don't have any trouble reading journal articles/pdfs, but a textbook with lots of photos and diagrams would probably not work well. I've always hated using electronic stuff for anything I may want to flip around in though, so that was never my intent with the Nexus 7.
I also love the flexibility of Android vs. iOS. The Nexus lets you drag and drop pdfs, movies, etc. if you plug it into your computer. iOS is harder to get stuff like that on (I think you'd have to load Dropbox or some other cloud storage) and load it all from there. Then you have to hassle with hospital wifi crap to access your articles.