I was driving the Tesla Roadster as well as the S P85+ - both cars performance is incredible. Didn't miss anything from the power track! But as Aldo says - lots of small things to improve - also build quality (sheet-gaps, etc.) is not there yet. Lookwise - I think the comparison picture with the Panamera shows that the car can easily play in this league. 

The i8 - seen it once in flesh and it was looking like a prototype car... very futuristic. Looks a bit to much plastic and not worthy enough for a 120k€ car. If it would look a bit more valuable or be a bit less expensive I think I could think about getting one.