Well, to add my bit, I've had 2 325's, 2 320's, a 306 xsi and a 306 GTi6. The 306 GTi6 will leave the bmw's AND saab (9000 aero owner now)behind on really twisty roads, closely followed by the XSi. However, I would say that as the roads become less twisty (i.e. no 90 degree bends) the Saab will definately outdrag all of them, the GTi6 coming a close second, and the 325 just behind. The GTi6, and to a lesser extent the XSi, are really good through the twisties where the passive rear wheel steering kicks in. However, should a sharp S bend be approached at speed there is a chance that the back end will overtake the front just after coming out of the final twist. Never done it myself, but this is according to the Peugeot guru - SKIP BROWN MOTORS.
I'm sure someone out there without first hand knowledge will disagree...