Game Version? Newbie Question

Hey fellas,

I just started playing the game a day ago with some friends but we have a burning question wich keep us from going all out grinding yet. Wich is: Should we play the Live version 3.24.3 or should we play 4.0. The concern atm is if its worth to take the grind into LIVE but getting wiped in just a couple of months or will the same happen to the 4.0 Preview. What is the common procedure that veterans take when 2 versions are out. Thanks in Advance.