Dragon Ball Super is a very interesting case. Starting July 5th,
super Dragon comic cum ball
My Japanese was horrible, my experience with Japan being fairly limited with only Anime. Gotenks also uses SS3 to fight an evoilved form of Buu and manages to fight him to pretty much a standstill. His power feels just right and 3.
This might not be an issue. Espalier Rant. So basically, the only thing that Vegeta needs to transform into SSJ3 is a good amount of ki to perform and control the transformation, just look at Gotenks.