Just using 2006-2008 I found pretty mediocre guys or already flamed out: Tyrus Thomas (same category as Amir Johnson), Shawne Williams, Brandan Wright, Spencer Hawes (jury is still out), Javaris Crittenton, Daequan Cook, Kosta Koufos, Donté Greene, DeAndre Jordan, Bill Walker, Jerryd Bayless
Fringe guys like: Oden, Mike Conley, Thaddeus Young, Michael Beasley, Anthony Randolph, J. J. Hickson,
Very successful one and dones since 2006: Durant, Rose, Kevin Love, Eric Gordon.
I wouldn't say that ratio is better really. There is a lot of crap in the mediocre/flamed out category.
2009 has some good ones like Blake Griffin and Tyreke, but also some guys who already appear on the way to flaming out like James Johnson and BJ Mullens. Still too early to judge that class though.