I have the Z-box on my 1997 Nautique with EFI GT-40. In the spring I updated the software to the new Revision R. This added the + Plus setting to mimic ZO. Previously it took some time to dial in the system, most notably was an issue where the system would run out of tolerance around 3 ball. With the new software this is no longer and issue. With this latest revision the short setup issue has been eliminated. The beep comes on almost instantaneously. I also noticed the system was more intuitive to the driver when hand driving if you spin at the end of your course. I train behind a 2008 196 with ZO and 200 with ZO. With the new software the pull is very similiar behind all 3 boats. If you are having problems with the new Revision R, I would first make sure your antenna puck view to the sky is not obstructed. Second, I would have the antenna puck checked to make sure is is good. Garmin did have issues with a few batches.