Bernie,
I am pretty new to the world of turning with only 47 bowls behind me. I also have not a lot of sandpaper to wood comparison, 40 years sandpaper to metal but that is a different story. There is a tremendous difference when you power sand as opposed to sheet sandpaper held up to an rotating bowl. I had read a lot of other posts and decided a few months ago to try Vince's Wood N' Wonders.com in Jeffersonville, Ind. I am impressed with his products and also his advice. I started out with the
3 3/8" size and just ordered the 2 3/8" two days ago. I also think highly of his knock-off souix quarter drill at $80.00 You can't go wrong with Vince.
I have no $$$ connection to him, I am extremely happy with his products and advice. Check out his web site, he has an educational part on it.
Good Luck,
Dave