I'm presently taking the obvious flaking paint off my bottom and will fair it with a RO 6", a bit. It's due for a full removal in the future. I think it was last done in the early 90's, all ablative after that. Ablative does build up over time.

I'm with you, the smoother the bottom, the better the boat will sail in lighter and lighter air(my goal). You can't miss with weight, the more you remove, the more the improvement. With bottom smoothness, I wonder when the return begins to negate the effort? For serious racers, there is no bottom too smooth.