Playing estate01d with a full 8 man squad my fps drops to 3.5 (all gfx settings are on max and i generally get >70fps).
The FPS drop ONLY occurs when looking directly (top down) at the car and my men at the bottom of the map, moving elsewhere on the map the FPS shoot back up to >70 again.
Edit:
It happens all along the bottom of the map i get a max of 6.5 fps moving to the top of the map i get the fps back.. also zooming out causes the fps to drop..