At about 25,000 miles, mySport started finding false neutrals, especially in the 1-2-3/3-2-1 shifts (traversing switchbacks - perhaps the WORST time to find a neutral). This was at the end of my warranty, but before the recall, so my issue was solved with a complete gearbox at the time. I would think shift behavior would be an indicator of the parts wearing excessively before a complete failure, but that is just conjectural . . .
Skip, I have always used th blue Lightweight in the gearbox and switched away from the red Heavy in the reardrive after my ten year battle with reardrive leaks. I found the red Heavy impossible to judge fill volume and suspect I overfilled for quite a long time, possibly burdening the seals. Other factors contributed to reardrive struggles, no doubt.