Busy, busy, busy.
To put it in few words: If I was to do it again, I'd do it the same way - the tiles stud well to the test of time.
To put it in more words: The only issue I had was caused by the adhesive I used. In hot weather. middle portion of some of the tiles was sagging a bit. I'm guessing that the adhesive closer to the edges dried up faster than in the middle so, in scorching sun it was getting playable again. The tiles were no coming off but on some of them it was visible that they fully don't stick. A gentle push towards the wall and all was good again.
After first season or maybe into the middle of the second one, no more problems.
If you are going to do it, find a good adhesive.
In any case; we are very happy with the thermal and sound insulation we got by using these tiles. The colours did not fade so, it's always a real eye opener for everybody who takes a peek inside. After all, how many people can say about their 14 footer that they have green bedroom, red guest room and yellow kitchen?
I wasn't a hippie but somehow "Peace brother" comes to mind.