Geoffers, yes, "training to proficiency" I think we call it. As a 3rd party trainer yourself, thanks for an honest appraisal. In your case, you have lots of relevant experience in operating helicopters which must be very beneficial. But (and correct me if I'm wrong) you have very little operational experience of flying some of the types for which you teach TRs?
The point being that if you do a manufacturer's course, you tend to get the good bits about the aircraft, but maybe not the bad bits which were not supposed to be there, and which are only known about following in-service experience by the operators.
There is most definitely a place for 3rd party and manufacturer's training, but not however in the context of a mainstream and very large operator, except when introducing a brand new type (IMO!).