Just tried it (080919) out, because for whatever reason my framerate drops to ~7fps after a few minutes in any of the DX clients, including 060929. Using OGLA, it ran well for the entirety of a trip from Cape Canaveral to Habana, with 60 fps average (about) even though I was running it windowed mode.
A few things I noticed:
-Shadows can do some "funky" things sometimes. I was using High shadow mode (since I didn't like the blockiness in VHigh) and noticed that occasionally shadows would cancel each other out and result in a not-shadow. Easiest way I found to see this was to take a DG in flight approximately perpendicular to the sun's vector, then put the DG between the sun and the camera. Everything goes dark (would be an interesting effect, but as is it's a little overdone), and as you move the camera around you can occassionally see patches of light and dark on the exterior of the DG where the passengers are casting their shadows. Very distracting, but not a dealbreaker.
-Habana was under ground; however, it allowed me to fly through the terrain to land. I just had the default download enabled, none of the high-res heightmaps or textures. Last time I used Orulex it put a "crater" around all bases--has that been replaced with needing to use high-res heightmaps?
-The moon looks kind of weird from the surface of the earth. It seems that if an effect similar to your nadir shade could be applied, it would look better, but as it is it looks a lot like a ball just kinda hanging there.
Other than those, though, it looked really good and ran very well. Keep up the good work!