second that. a dd and vdrive are somewhat 2 different boats for 2 different markets.
you mentioned that you will spend most of your time tubing. guessing(and just a guess) that you will have a lot of kids on board? if that is the case, I'd hold out for the right vdrive. they will appear to have much more room and, imo, are a much more "social" boat as you don't have that engine cover in the middle of the boat.
if you are truly wanting a vdrive and buy a dd, you will kick yourself when that vdrive you wanted comes to market in a month. v's will be more money, but like max said, do it once and get what you want