At a trackday at the Moto GP track at Assen(NL) half a year ago I could keep up with a 997GT3.1. The guy told me he was trying to get me out of his rearviewmirror but he couldn't. LOL
I toasted a few Porsches before also in normal traffic/twisties, sorry....
stock E90 M3 6MT.
It depends heavily on the driver.