Anecdotally, most iPad photographers I see in the real world are using 9.7-inch iPads, not the Mini.) And the sort of iPad users who are pushing the performance limits of the platform are the sort of people who’ve preferred the 9.7-inch models all along. In short, I think the Mini really is more of a pure consumption device, and the Air is more of an alternative to a MacBook.
I think that is a great point from John – Although you can use the mini as a laptop replacement, it really is the bigger sized iPad that is the true laptop alternative – bigger screen for photo and video editing, two handed typing etc. If you are on the fence on what size to get, consider that before purchasing.