John Gruber writes about the Retina iPad Mini.
But this new retina Mini feels like a two-year upgrade over last year’s. There is no longer any compromise over display quality or CPU performance. All of the advantages of the original Mini remain — smaller size, lighter weight — and there are no drawbacks. When the full size iPad went retina, it was a two steps forward, one step back sort of upgrade: you got the beautiful retina display, but the device got noticeably thicker and heavier to accommodate the battery that was necessary to power all those pixels and maintain 10-hour battery life.
There is no drawback to the iPad Mini going retina. There is a negligible increase in weight, and an even more negligible increase in thickness, but the differences are so slight I honestly don’t think they matter. The old and new Minis are so close in thickness that both fit perfectly in Apple’s new leather Smart Case (and the same polyurethane Smart Covers fit both as well).
He has some advice for you if you are undecided which iPad to go for.
iPad Mini or iPad Air? It really just comes down to size. I think the Air is better-suited for those who use their iPad as their primary portable computer (or primary computer, period). And if you use your iPad for things where bigger is better — watching video, reading comic books or PDFs or print-derived magazine apps (where you’re better off with a screen that is closer in size to that of the printed page), or for on-screen touch typing — well, you probably want the bigger display of the iPad Air.