After the camera-changes the camera rotation is now very sluggish, as if there has been added a new type of smoothing or acceleration to the camera rotation.
If I adjust my FoV using the new slider, the camera rotation is back to normal for about 3 seconds before slowly fading into to the new sluggish settings. This is very noticeable and easy to reproduce.
[edit] After adjusting my FoV slider, my FPS drops to 30-33fps for about 3 seconds before gradually going back up to a steady 50fps. (it is VERY responsive during low fps, unresponsive and sluggish when back to higher FPS.)
Capping fps at 30 using built in Frame Limiter as a temporary fix.