I own a SN 196 with GT-40 engine and Z-Box latest version. I also ski behind a SN200 with Zero Off. I'm not a short liner as 28 off at 32 mph is where I'm at. My questions 1.- is there an appreciable, noticeable difference between zero off and my z-box? Both systems are gps and mapped to our course, both have same options for pull type settings. My opinion is that I perfer the wake on my SN196 and seem to not be hammered by the pull of zero off. Course times are measured on both systems and are within allowance. 2. Other than the Z-Box not being approved for tournaments, am I hurting my progression by skiing more behing the 196 with z-box?