I've been pretty happy with .99 & my appleberry theme. The lock lag is still annoying - but everything else is pretty good. I do miss the speed of .90 - but the stability of .99 is nice. I heard accelerometer response has been improved - but that's it.
With these new OS's leaking out - would you say it's worth upgrading? I haven't really read anyone raving about the new leaked OS's past .99