I can proudly say that I smashed the limit a couple of years ago in a single engine piston. 9,500ft on descent over Tulla into Moorabbin, SR22, 200 indicated, add for TAS and a massive tail wind giving 270 knots. Can't complain.
Its IAS anyway, not TAS and certainly not GS. Just as well as the GAM shrikes at AD and EN would have to slow down most nights in winter.