Steve76:
Category A has nothing to do with being able to maintain MOCA in IFR, at least not that I'm aware of.
xnr:
You can pretty sure that the folks in Ottawa who made the decisions are aware of what Category A is. To refresh your memory there are normally four different situations for Category A - long runway, short runway, ground level helipad, and elevated helipad. For example, at least one helicopter has a limitation in the elevated helipad performance relating to the helipad size. You can't use Category A performance and limitations if the helipad is smaller than that size because of touchdown dispersion.
Read the Advisory Circular for Part 29 helicopters, found in the FAA web site - it's pretty illuminating on how the testing is done, and what the performance figures look like. I know the Bell 430 Category A Flight Manual Supplement (FMS) is nearly as thick as the 'normal' manual, and it is not easy to work out - not because Bell or Transport Canada are trying to be difficult, but because this is now as complex as calculating takeoff distance and V1 speeds in big fixed wing airplanes.
Remember this is all about trying to ensure a level of safety for helicopters with the capability to carry a lot of people. Life ain't simple anymore!