I have been using GE4 beta 2 for about a month now. The following is my feedback:

Performance: on a x86 (Intel P4 3.6 hyperthreaded) is terrible. Much worse than on previous versions. I don't know if it is a server issue or a client issue, but it is SLOW!

Navigation: #1) I find the new controls too slow to be very useful. They may be ok if working at full speed, but changing a heading and waiting 10 seconds for it to respond. #2) When dbl-clicking to zoom into an existing placemark that is near ground level, the "camera" drops below ground level, then bounces back into a birdseye view.

3D Buildings: #1) SketchUp is just plain limited. Not many import/export options. #2) Most 3D assets are already created in an existing 3d program: 3ds max, Maya, etc. Of course, the native model format for GE4 is Collada, which import/export filters are available for most common 3d apps (max, maya). #3) However, about 1 out of every 5 models I try to use in GE4 will not work. (I'm contemplating writing a tutorial that will cover how to use max and maya for GE4 model authoring...is there interest?). #4) I am currently converting an entire 3d representation of the entire University where I teach...it will be a great tool when it works flawlessly.

Asset Packaging: #1) More documentation regarding asset packaging (KMZ, etc.).

Overall, I think GE4 will be outstanding...but I wish GE development had a place for serious testers to forward feedback.

Any comments?