Just flashed this on iPad mini 2, but in terms of animation stutters, lags, glitches, etc, iOS 8.2 beta 5 did not improve it AT ALL.
It seems like the annoying a second lag that happens when going home screen is even more frequent, just like beta 4, I noticed. Of course, you should turn OFF reduce motion to notice this. And orientation change animation stutter, spotlight keyboard pop-up stutter, and all others are still there.
Really, really tempted to sell this POS..
I am also tempted to sell my mini 2 for the same reason. And I probably won't buy another iPad again. I shifted even most light tasks back to my macbook, because the experience went downhill with every version of iOS 8.0. Apple needs way to much time for fixing these bugs.