gums;
As PJ has noted, the mach buffet and overspeed have a different "feel" than a no-kidding aerodynamic stall.
I have experienced Mach buffet once, very quickly, almost certainly 'g' (and of course, AoA) related. That is where my characterization of the buffet as "sharp" came from. I have never experienced low-speed buffet except in simulators, all Level D, including the A330 simulator, and it is to this that I now need to clarify/change previous comments.
After my simulator work last year I wanted to understand how accurate the simulator reproduced the actual stall behaviour. I discussed the matter informally with those who would know, and the comments I received are echoed in the Wainwright papers cited by
PerkyPerkins, (the other reason I thought these two papers were important reading, the first being the handling of trim in the stall).
Essentially, for reasons now made clear I am led to believe that Level D simulators DO NOT replicate flight and aircraft handling characteristics at, and beyond the boundaries of controlled flight.
Therefore my comments on the nature of the A330 at/in the stall regarding buffet and similarities/differences with Mach buffet, would not, I think, apply.
Personal opinion, but I suspect the 'bus is very tolerant of mach overspeed until maybe 0.9M or so. So get the nose down and worry about mach later.
Concur. Where there is doubt and a choice (ie, altitude), high speed is better than low speed, anytime. The airplane is indeed tolerant of high speed so get on with the standard recovery to a stall even if in doubt.