I've got yoko avs550 db - w rated, in that size. Very happy, lots of dry grip which is what I was after. I drive on the track whenever possible, have yet to try these on the track. They are a quite tire, I also find them a firm ride compared to my last tires ( yoko A539 - I was disapointed with those ).
Good luck - in the Aust' market there is very little to choose from at a reasonable price. A performance Michelin for us is over double the price of the yoko - if this is not the case for you, I would try the Michelins - from past experience on big bad Mercs - Michelins are fantastic on big german nasties - like ze e34, yah ?
Stacy Au
535i 5 speed '88
Track pack = camber plates/king springs/m5 Nurb' sways/17"bbs 3pcRS e34 spec/chip.