Go for it. With every new driver you
should see an improvement in performance, satbility and compatibility. That's the purpose of improving the things. Of course this is a (very) idealistic view.
The 177.xx drivers saw some changes, particularly under XP they changed the way shaders were handled. AFAIK the 178.xxs should be building on that and offer an improvement.
Only way to find out is try them. Easy enough to roll back.