That's quite a collection, maxjamie! My list is similar (300zx, GTi, 996TT, 911s, A3, A4, S5, S6, 330ci, 760i, 850i, 650i) so hearing your experience on the switch is hugely helpful. That makes me want to zero in on the P85.
Again - thanks to everyone who has responded. It's been a huge help.