Nick,
2G equates approximately to a sustained level turn at 60 degrees of bank, if I remember correctly.
The manoeuvres I have experienced as required to induce jackstall are beyond that.
If the aircraft are flown within their published limits there is no problem.
However, I may well agree that Sikorsky aircraft may be built with more margin in hand in some areas, obviously in the case of the S-76 and other aircraft with an input from your good self. It doesn't mean to say that another manufacturer's product is unsafe though.
