Well your going to get a lot of different opinions on this one my friend. I have not been in a 15 MOJO. I have however been in a few MB's and they changed up a few things on the inside but the quality of the MB is still the same on the interior.
With that being said the wakeboard wake on the MB is going to be very good right out of the box with maybe 400# added to the nose and you would never have to add another drop of weight to it. Now the surf wake is a whole new animal with the addition of the Switch. (Haven't used it yet)
The MOJO on the other hand is totally redesigned and unproven in the market as of now, hence the fact no consumers have not used one in the real world yet. I suspect if they incorporated all the New Supra technology into it, it should be nice.
If your in the Dallas area one thing I would take into consideration is the Dealer factor and the guys at TXMC/MB are second to none when it comes to sales and service. GOOD LUCK!