Doesn't part of the problem lie with the fact that Mr. Robinson didn't design his helicopters with training in mind.
Although to my mind, the R22 is the "twitchiest" of all helicopters, the R44 isn't. However, even if you were flying a Jet Ranger, a Cessna would, in comparison, feel as stable as the Rock of Gibralter!!!
One thing that cross my mind is the geography of hangars and aprons. Maybe operators need to consider where they position their landing spots and how they will be approached.
Cheers
Whirls