@1Louder has a good data point there. As a wear surface it might not be as high a performer as a Line-X product. But it is easy to re-coat as needed.
Several years ago, I did an entire vehicle (1989 FJ62) in two colors, and it turned out really great. As has been mentioned, a good prep and sanding is the key and most of the work.
This is a two-part system, so when you mix it up, you gotta use it up! No trials, no gathering the tribe to see if they like it. Once you mix, you go! Be ready to work.
I covered mine, two coats, two colors in one 14-hour day with the help of my capable son for about 3/4ths of the day, so it is a lot of work. All the prep work was done before that day and it took me a week at a couple hours / day to get it ready, but it needed quite a bit of work.
How durable? I sold the car because the guy really dug the look. He lives down the street and has basically mistreated the car and honestly I haven't looked at it up close so I can't say how it's holding up. If I can somehow sneak a peak, I'll give you some feedback.
Long story long, I would do it again as a lower-cost alternative to getting a cheap-o paint job - totally worth it IMO.
Dan.