One thing I know of is that it does quite some blade erosion. The R22 or the R44 have pretty good stainless steel leading edges on the M/R blades that slows that erosion. However, the T/R blades are in the Robinson more sucseptible to erosion than the M/R ones. Also, any prolonged flying in heavy rain should be avoided if possible. That is just my opinion.
Anybody correct me please if I am wrong.