i had a motion pro carb sync pro for awhile. tested out on my 4cy VFR, and it sucks big ones. Sold it cheap and picked up the "Harmonizer" a guy makes and sells these on the ADVrider forum, its amazing. just did the 250r a few days ago and it was precise and quick. For $119 shipped you cant beat it.
http://advrider.com/forums/showthread.php?t=701625