I've recently had both Pirelli PZero Rosso and Michelin Pilot Sport 3 (235/40ZR18-95Y) on the front of the S210, and still have Pirelli PZero Rosso Mo (265/35R18-97Y) on the rear.
I found the Pirelli quietest, smoothest and most comfortable ride, but the Michelin have very much better grip, particularly in the wet. (Btw I've often found Continental to use a particularly hard rubber compound, and Dunlop to wear out fast)
Now these are new tyres, I had to change the front Pirelli PZR for the Michelin PS3 because the monkeys had fitted the wrong size to the front, 245/40 do not fit on the front this car, they foul the arches. Plus I'd had a couple of 'moments' with the Pirellis under braking, and steering in the wet: the dry steering also felt rather heavy and vague. The Michelin PS3 fronts are absolutely sure footed wet or dry.
The Pirellis on the back have only let go once on a wet bendy hill, causing the ESP to light up the dash like a Christmas tree. Despite my lead-foot problem the car just self-corrected and stayed on course like it was on rails. This is reassuring because I have had problems with Pirellis in the past on other cars (throwing tread off carcass; snapping a tyre band), but this is probably the last time I shall ever buy a set of them (I said that last time too). I have used Michelin sets in the past too and have never had any issues with them at all, they stick to the road like glue and they wear well. I can drive on Michelin in the confidence that they will not let go when you need them, sadly not so the Pirelli. ymmv
