I've most of the Xtreme upgrades too now, except for blades and grips, and after a full reset it flies way better! I can 'set' it on its own column of air and it'll stay put with just little inputs! So my guess it's either the limited movement of the flybar or the alignment of the bladegrips. Have you checked bladetracking?! It's becoming more and more obvious that it should be dead on. Mine still isn't either, the linkage of the flybar i got didn't fit, so i had to use another one, but now the linkage cant be adjusted far enough, maybe thats the case on yours?