I've just been on PTS for the first time in a few days and: Firstly, the performance is quite a bit better than Live on the same graphics settings. So good work there. I'm generally 40 FPS GPU bound now which is an improvement over 25-30 FPS CPU limited before. Second, though, occasionally (only while moving I think but that might be coincidence due to very specific locations) the screen 'flashes' what appears to be a view of the terrain with no buildings, including the one I'm standing in at the time. I'm running a GeForce GT 650M on Low graphics general setting and otherwise all defaults.
