Fit and use
It fits me perfectly. I am 177cm and 80kg and wearing usual M sometimes S.
It is a very flexible material and I've never felt that what pushes or pinches. I wear it as a bottom layer in the temperature range of -5 to + 10 degrees (warmer it was not as yet) while running.
Benefit
What it delivers? For it was important that the sweat away neatly, because I find it uncomfortable and very cold when the sweat collects under the first Aachen layer that will not come before now. Since this is very well clings also rubs anything.
Processing
The build quality is also very good, it has now already gone through several hundred kilometers without any signs of wear. I notice no seams while running.
I wash it after running always with your hands and wring it out after that, it then dries within a few hours. But washing is also no problem.
Price-Performance
Price / quality I would describe as well (starting from the EIA), for I have no good experiences with sports stuff from the supermarket, but which are usually significantly cheaper just not do what they should.
If questions are of course I try like to help.