My Excelleron has a YS 110 with a 16-10 APC prop and Wildcat 30% Heli fuel. It will come off the runway and go straight up until I cannot see it any more. I have run YSs in my helicopters and pattern models since the 70s and have always found them to be plug and play. I ran a YS91FZ in my G-Trick for years, replaced the 91 with a 110, destroyed the model in a b1rd collision (the turkey buzzard lost!), replaced the G-Trick with an Excelleron and have been thrilled with the performance of the model and the motor. I have flown the same model with a Saito 125 and it was fine but I prefer the 110 for simplicity and fuel efficiency. Everyone has their own opinion about stuff, and everyone elses stinks, except mine <G>
Try the OS and see if you like it. It might be great.
Gordie