Overall, the iPad mini 4 is a very good device, and a return to form of sorts for the mini line. It still lags behind the iPad Air 2 in a number of ways, but for those who prefer the mini's smaller form factor, it's an appealing tablet.
The thinner, lighter design is even easier to hold than past iPad minis; A more powerful processor boots up the iPad and opens apps faster; Rear iSight camera has been upgraded to 8MP, with slo-mo video recording and burst mode shooting; Colors are sharper and more accurate in updated display.
Still often feels like a step down from iPad Air 2; No 3D Touch display; 16GB capacity will be too small for most users; 1.2 MP iPad FaceTime camera feels outdated; The design has been tweaked enough that old iPad mini cases won't fit.