A day later, I tried the same with no towel and shirt and it is bearable. After a few minutes is a relaxing and just in the evenings you might think the same fall asleep, if it does not tweaks at one point or another something. The skin is on the way back heavily loaded (see Wikipedia:. Body-suspension), yet it feels any different, so that one can generalize at all.
One tip I have, however: less reverently examine the hard tips, easy drauflegen ;-)
The build quality I find so far good.
Now I just have to find a job around my shoulders and neck maintain an optimum battery dot. For the flat back that is not a Poblem.