I think it depends on the boat or application. I know someone who has a conventional bottom 42' Tiger with 1,000's & 6's and it porpoises like a B*tch. You have to run the tabs pretty aggressivesly in this boat to stop the porpoising....it slows you down almost 10mph!!! Another friend of mine (had) a 38 TS TopGun that ran like a dream, no porpoising and you rarely had to use the tabs. It flys extremely level.