Not sure you're 100% correct on some of your assumptions here.
Yes, the Rotorway has a low inertia like the R22 but due to a different blade design your have much more time in the Rotorway to drop the lever in case of an engine failure, perhaps double or treble the dwell time.
In the UK at least, all Rotorways have extensive checks for the issue or re-issue of a permit to fly annually, plus all servicing has to be signed off by a CAA certified engineer...so quality is fairly uniform in the UK.
I agree with the greater service time of R22's etc issues are much more likely to be ironed out...and that makes the Robinson incredibly reliable...the Rotorway is certainly not at the same level. Plus the limitations of a Rotorway are tighter.
Pays your money and takes your choice I guess.