running in,
I put the 450 lbs as a shot at that correction from brochure to service weight, based on some facts that S92mech posted a few months back. I believe the weight of a good offshore S-92 is about 16,750 lbs ready for pax and fuel. I will search for mech's post to correct that.
This includes most of the goodies you list, at least as one pro offshore outfit spec'd it. the nose to nose between a 225 and an S92 is no contest, the S-92 has about 1300 lbs more payload, or 130 NM more range, depending on how you want to cash in the extra performance. The aircraft look as if they are within 600 lbs if you use the 225 brochure, but they do not add the weight of the crashworthiness they have as a yet uundesigned "option."
The "battle" between the 225 and the S92 has already been waged. Literally across the board, the 92 has won. Only at Bristow (see a pattern?) has there been any concept that there is a horserace, elsewhere, compliance with newest FAR/JAR has been required by the poor sods who must sit in the things, and the 225 was eliminated at the outset, due to its safety shortfalls.