Lol! I’ve lived with on-street parking for the last thirty years. Practice does hone your skillsNope, no incidents.... I don't use it very often but sometimes when parallel parking and I don't want to look like an amateur. Even though I'm not. But it does a better job than I can
My w205 c63 won’t even attempt spaces I can get my s211 into. Parktronic is a godsend, but just yesterday I put the s211 into a space that was 4 ambers on the back and 1 red on the front with a reverse in and just a single pull forwards. I even impressed myself. And no, it wasn’t a Paris style park. Didn’t touch either car. It was a case of necessity. It was the only space for nearly a quarter mile of our house. My wife couldn’t believe I made it - she watched our neighbour try and fail repeatedly to get her Juke into the same space.
I pulled up outside my house after work one day & was doing a lot of steering wheel twirling to get into a space when a message came up on the dashboard "Do you require assistance with parking?" ...I thought hello what's this & pressed "yes" & the steering wheel started turning by itself. Whoa! And I stamped on the brake Still not used it, same as you I don't fully trust it but I must find a deserted car park one day to try it, that way I might trust it after 
The only problem with parking that close are the drivers in front and behind might not be so careful pulling out or reversing to pull out.Lol! I’ve lived with on-street parking for the last thirty years. Practice does hone your skills
Sadly it goes with the territory. If your car lives on the street you are going to get the odd bumper mark here and there occasionally. I’ve watched people touch bumpers a lot over the years. Some people can’t park for toffee. Busy town on-street parking is not for you if you are precious about your car. I use my old E class as my daily because it’s not mint by any stretch. I keep the nice cars elsewhere. I occasionally have them at home, but it’s not relaxing!
These systems have been refined over a number of years, by the looks of it Mercedes use the same basic system as Toyota use on their cars. I had a 2007 Prius for a while in 2009 and it never once failed to park automatically, correctly...
I could be wrong, but I think on the 204 you have to do the wheel-twirling bit yourself. Must admit in 3 years of ownership I've never used mine.
Just as well you may never get to switch it off again.
This is what worries me - have heard the same elsewhere, so will stick to me doing it - if I kerb them then at least I can only blame myself!When I was filming my HOWTO video, I managed to kerb my alloy when it was in action
