Everyone's different, so ymmv. For myself the Air2 is much less a handheld tool than a Mini. The majority of the time I use an iPad I'm either standing or sitting, holding it with two hands. The Air2 for my hands is a bit wide for thumb typing in Landscape mode, and for the short time I had it did not balance well in Portrait for fast typing.
I sold my iPad2 a bit too soon, and was disappointed when the iPad3 came out. Waited and eventually bought an Air2, but returned it for the reasons above. If a Mini4 does not come out by WWDC, I may bite the bullet on another Air2 for which I love the screen quality.