There are many people with P85D and 19" wheels. I personally think they look better than the 21" wheels (and realize that I'm in the minority). I have driven both a P85 on 21" wheels and my S60 on 19" wheels on the same streets and commute and believe that the 19" wheels are quieter and provide a gentler ride. Oh, and then there is the cost per set plus the shorter life span. Yes, I understand that on 19" wheels I may only get a 3.5 secs 0-60 time. I think I'll be OK with that. (actually, I haven't seen hard numbers on that, just that it would be "slightly slower" as they provide less traction)
I have only good things to say about them. Great drop in replacement. Tesla really should offer a grey 19" turbine wheel. It would sell.