when I think overheating I'm thinking the car is getting quite a bit above 200.
Does it go above 200 when sitting in traffic?
Some will say you will loose 1mpg because the engine is less efficent, some will say dropping to a 180 has no impact at all on fuel economy
I personally run a 180* stat all year round and have my fans turn on and re-programed the fans to 185 on low speed and 195 on high.
It seems as if your car is operating as designed, it should constantly be right around 200.
Dropping to a 180 is more important when you are concerned about pre-detonation (aka in terms of a supercharged car which has a smaller pulley on the blower)