Post #6 of this thread explains it well: http://www.mastercraft.com/teamtalk/showthread.php?t=27486
"Early 2008 -The world of speed control and tournament skiing is about to be turned upside down by this ZO/PP deal. To make matters worse, ZO and PP are battling over the patent for the GPS differential speed control technology that makes ZO work. PP releases StarGazer. MC releases the 08' TT 197. All 100 boats will have dual installs via the same E-controls multiplug ECM. MC is not allowed to physically install the ZO head into the TT 197 dash, due to some sort of licensing or marketing agreement, probably due to the CC/ZO relationship. TT drivers must do the install themselves. No biggy, takes 5 minutes. Production MCX's still have the standard ECM that cannot talk to ZO. CC promo boats will mostly be ZO. Malibu is in the dark - without the ability to do a ZO install.
Summer 2008 - PP and ZO reach an agreement. ZO gets all OEM drive by wire speed control business starting with the 09' model year. Skiers are complaining about early versions of ZO. Diehard perfect pass skiers are flipped out because they can't even upgrade their boats to ZO to practice. The only time they see it is at tournaments or upgrade for 50-60K with a new DBW boat. StarGazer has it's own set of issues. The forums are alive with arguments and bad info."
Possible to convert any Vortex 5.7L to E-controls ECM, varies on how involved and expensive.