I build alot of flash based E-learning modules, quizzes and interactions that help make the models available to my anatomy students anywhere they have internet access.
The cross-platform nature of Box.com has allowed me to access my documents stored in it from the android tablet on loan to me, an ipad, and an Iphone as well as the web. This will more than cover the majority of devices students might have to gain access to material posted within Box.com
Size makes a difference. However seamless and pain free Dropbox is, we are limited to 2Gb of which I am painfully close to using up. I find myself deleting or moving other files just to allow new material to fit. Box.com will more than take care of storage needs though the granting of access to others is somewhat clunky compared to Dropbox.