IMHO - the iPad is a terrific piece of kit used in the cockpit, all previous comments understood. One of the best apps that I've come across (and admittedly I am perhaps biased as I create .pdf eForms alongside the 'day job'!) is Readdle's Fluix and as an stand-alone option - PDF Expert. Fluix especially, as the workflows, JavaScript supported capability, Sync. and other functions - makes it a breeze to update and deploy, receive completed documents like; Journey Log, Loading Forms, Cabin Forms, - all of them! and all manuals can be 'loaded' as well. Don't think the larger size iPad is necessarily a requisite, you can always 'pinch n zoom', set larger text fonts, side-by-side display (that is a little tough on the smaller screen real estate admittedly). And the iPad as a platform has plenty of supporting documentation from app providers like Jeppesen, that if say using EASA Part-SPA EFB - makes life a lot easier in gaining NAA approval of use, apps also.
All in all, I love the iPad - simple to use - and they don't get much simpler than me ;-).