My university now gives all students free 365 licenses, which is great. I enjoy Office for iPad (I mainly use Word). Word is a superior word processor compared to Pages, that is just the way it is. Pages only strength is creating beautiful documents.
I miss Dropbox support.
For corporate users, the Office suite is a given. I mean, do you have a choice?
However, for student/academic and creative use, I truly think it's time for Mac/iOS users to move beyond Word. While Word is good to have for sharing with colleagues/teachers for markup, it is not the best platform for productivity.
For day-to-day note-taking, my app of choice is MacJournal (Mac and iOS), which has the benefit of letting me browse between my various notes without having to open new documents. The Mac version also has a great clutter-free full-screen typing mode.
For those who think and write in list form, Omni Outliner 4 is a great choice compared to bullet lists in Word.
Since I personally do not think in list form, I find that the combination of MindNode (mind mapping app) and MacJournal suit me well.
All of the above are Mac apps with corresponding iOS ditos, and they have sharing via Dropbox or iCloud.
For larger writing projects there are other wonderful Mac apps, e.g. Scrivener, but since this is about iPad apps, there is no point in going into detail.
Another must-have Mac/iOS ecosystem app for those in academia (yes, including students) is Bookends (which in turn integrates wonderfully with Mellel, another great independent developer word processor for the Mac). Bookends is a bibliography app for the Mac, but it also has a free iOS app which allows you to always have your reference list accessible.
My point with all of this is to say that unless you get a 'free' corporate or academic license, there are many superior options for writers using Apple hardware. Dare to let go of the MS Word mindset; you will be happy you did! Considering the cost of 365, writers could purchase several of the above for the same price.