There's no doubt lots of statistics out there re piston vs turbine, but I'll rely on my own experience to pass judgement. In 3000hrs of Robinson flying I've had 1 stuck valve(R22), & 3 x magneto failures(R44). About the same turbine with no failures - Speaks for itself. My concern with R44's doesn't lie with the engine, but rather the MR Blades. Waaaay too many delamination cases for my liking. Otherwise a fantastic machine to fly & I don't think you can go wrong getting endorsed on one as they'll be around in great numbers for a long time yet.