I just flew it a month or so ago for an article in Defence and Public Service Helicopter (article coming out soon), and it was superb.
I have probably less than 2 hours total in any of Frank Robinson's wonderful machines, and this was amazing. Piston engine? If you couldn't hear the noise, and just concerned yourself with handling the machine, the combination of fuel injection and governor makes this just about like a turbine.
Now if it only had an AFCS at a low price... (and I know someone - (not Robinson - so don't bother them) who is working on one....)
Shawn