If it runs good your probably fine. I think on a dyno you may see some loss. But if you dont need every bit of power your probably fine. Some down falls that I can think of would be, Less gas milage, maybe a lil more build up in engine, and a slight bog.
Just curious what you air intake is like, (lid, snorkle....) Also temp where you live. I have 340's and after two days of riding the plug is brown. Clips is on 4th pos..