I had problems early on. A small spring was upgraded and probably would have solved everything, BUT I made a big fuss, made them tear it apart, and on my own dime, bought the 2'nd gear and syncro that have the later part number. (The spring, which can be replaced without cracking the cases was all I should have had done!) It worked great for a couple of thousand miles, then I missed second while trying to pull a fat wheelie (going into second, there were Harley's involved, it's not worth repeating). The subsequent teardown and rebuild went back to the original parts number 2'nd gear and syncro, but still with the updgraded spring. The bike shifts fine, has been to NY and back, about 10,000 miles since it was worked on, no problems at all.
And by the way, my Hodaka Ace 90 was a constant mesh tranny, (very clever really) and the Rocket three is MOST DEFINITELY NOT a constant mesh transmission.