I've always been impressed with DCS implementation of VR. But in 2.5, they really need to sort out the performance hit with MSAA enabled. Either you cop a big performance hit or you put up with a lot of shimmer and aliasing. For me, 2.5 performance is therefore much worse compared to 1.5.8 as i like and feel its necessary to have MSAA x4 enabled.
I also think the lighting is a over done, and some of the cockpits need re-working such as the A10C. Perhaps a separate gamma for outside and inside the cockpit may help here as a temporary fix.