I own an S85 (19", no-pano, + air suspension) since Dec. 3, 2012 and it is the first and only Model S I'd driven until 2 weeks ago when I was given the P85 Loaner (21", +Pano, no air suspension, + 3rd row seat) while my car was at the service center for it's "annual" maintenance and several lingering but minor warranty/Technical bulletin issues for a full 2 weeks. Over that time I put about 900 miles on the P85 loaner using it essentially identically how I use my S85. Thought I'd share my first hand extended experience in case others are wondering if they made the right choice or are trying to decide which model to get. *I did very little highway/distance driving beyond about 25 miles on a single trip, so can't/won't discuss highway cruising. **I spent significantly more time with 'spirited' driving with the loaner than in my car which may have negatively impacted the overall energy efficiency. The P85 feels "lighter", the torque really allows the car to lightly take off from the line, my S85, in comparison, feels heavier both with launch and slowing. Not noticable with cruising. My average Wh/mi in the P85 was around 330, comparably I have been getting around 300Wh/mi on average in my S85. Even in situations where I wasn't driving in a "spirited" fashion I struggled to see the same numbers I get in my S85...one familiar 5 mile segment I would get ~310Wh/mi where I typically get 280-290Wh/mi. Not sure if that's attributable to the bigger rims, pano roof, lower efficiency of the drive train, driving technique, or (most likely) some combination of those. In any case, it is much easier to get better energy efficiency in the S85 and for those whom maximizing range is highly important the S85 would be a key choice. My S85 is much quieter than the P85. The Pano roof and tires may be factors, even discounting the "whine" of the motor in the P85. I could hear the motor at times I never hear it in my car. The 21" rims are much more prone to hitting the curb. It is hard to drive the speed limit in the P85...very hard! The Alcantra roof liner and trim on the seats are a very nice touch, as are the metal pedals. In all, given the performance improvements and these added features the "up charge" for the Performance is, I believe, very reasonable...though I would, personally, go for the 19" rims for the lower cost, less frequently replaced tires and better energy efficiency. I noticed that, compared to my S85, there seemed to be an incongruous drop in energy that was much more dramatic. In other words, I would drive 10 miles, but see a loss of 13-14 miles of rated range even with similar Wh/mi ratings (certainly not different enough to account for a 4 mile range difference), whereas my S85 seems to track quite closely on a miles traveled to miles used rating. Pano roof is much quieter than I would have expected (at 80% open setting)--I'm sure that's true for an S85 with pano too. Many times, under just mild to moderate acceleration while turning sharply I would get a single rear wheel spin and then the traction control would drop out power temporarily. Never experienced that in my S85 The real difference in performance, in my experience, is in the 0-40 MPH experience. The P85 just jumps out there with a whiplash inducing jolt. My wife complained I was giving her headaches. Above about 40 while there may be measurable differences, I don't really appreciate them in practical driving/usage. Again, to avoid defensive responses, the P85 is probably measurably quicker in the 30-60 acceleration range and even above too, but it just isn't nearly as noticable to me. Glad to entertain other experiences/comparisons and I hope this helps someone.