JustOne
Ryder Cup Winner
KBS and PX were both designed by the same guy, Kim Braly (the KB of KBS) and are both intended, in different ways, to give a flattish flight with lower spin than TT DG which are quite tip heavy. KBS have a different weight distribution, described by some as 'counter balanced' although that is not really the case, and they feel a bit lighter to swing although they really aren't. There is a newish KBS model called the C-taper which has a lower flight and less spin, and a new Project X coming out which is similar.
You should find that both PX and KBS launch the ball a bit higher, but it stays on a flatter trajectory, than TT DG due to lower spin. PX can feel rather harsh, but KBS feels better.
All very good but is it still possible to hit them fat?
PX5.5 is more than enough for me,... even more so in the colder months when layers prevent a really decent swing. Put me in Florida all year and I'd take 6.0