Collision ModelSeems fine to me and bug free so far. The "wall of trees" no longer exists and I like that. Individual trees stopped the motion of an M3 by headon contact, reversing into a tree, and side-swiping a tree.
Gunner positionsBy tilting the the M3's gun down and rotating, the gun seems to "stick" for a moment and then catch up with the view.
DitchingThe P40E cannot do a gear-up belly landing. It results in flopping and an instant trip to the tower. The 109G6 (which, btw, is beautiful) skids properly. However, the ground/metal combo seems to have a very low coefficient of friction... took a while to stop even at low speed sliding
LightingPlane models seem rather dark even at noon sunlight. Fuselages seem rather dark. It doesn't feel like daylight... feels like a flashlight is shining and there is very little 'scattering' of light into the atmosphere.
ShadowsATI Radeon 9600XT card here and the P51D's shadow looks great. It does not show through the plane or cover anything. However, inside a hangar, the shadow still appears on the roof or ceiling.

1.2ghz CPU
ATI Radeon 9600XT
512 ddram
K7S5A mobo
Audigy Sound
WinXP