I had a chance to drive a P85+ loaner with air and 21s while my 2016 85D (air and 19s) was in service. Just wanted to give some reactions. This was an older non-AP car, VIN 23XXX. With the + suspension I was expecting a pretty uncomfortable ride but man that thing drove so well! Sure footed, but absorbing big impacts like sunken manhole covers much better than my 85D. No body roll whatsoever, and no floaty feeling like my 85D. It was a real blast to drive. I wonder if I can get some of that ride quality by moving to 21s. Seems counter-intuitive, but out of the 5 Tesla's I've driven now, the two that rode the best were the P85+ and the P90DL, both with 21s and air.