I don't own both yet but I will on Friday (picking up a factory demo 2013 XU with 195 miles on it).
We own a Tesla 85D. It's amazing. Smooth, sporty, beautiful and fun -- the hype is well earned. If you are on the fence and can afford it, you will not regret it.
I would not worry about buying a Tesla that was involved in a collision, even if it was a salvage. Tesla has pretty strict quality control over its cars. If a car is in a bad accident and receives severe damage that its computer can detect (say, an airbag goes off), Tesla won't even reactivate the car unless it has been repaired at a Tesla approved shop or is subsequently certified by a Tesla technician (if you search over at TMC, you can find a bunch of threads on this, as well as some sour grapes from people who wanted to buy damaged cars, only to risk not having Tesla enable them). If you can verify the work was done at a Tesla certified shop, you can be assured they know aluminum well and received extensive training straight from the manufacturer.
Good luck, and enjoy.