I have just completed my first Annual on RMQ. 200hr in service. I have the 912isSport and Airmaster propWith 75" blades. I experienced a slight increase in vibration so decided to send the gearbox off to Rotax to have it checked - result was that there was a need to replace gear set and dog hub that were worn on ramps. No cause suggested by Rotax - said that the 75" WW blades might contribute. I am talking with Airmaster about that now and will be interested in their opinion.
Only other item needing attention was the radiator that developed a slow leak - although I have had it repaired, I bought a new one and kept the old one as a spare.

All set now for another year of adventures!

cheers

r