andrei_eremenko,
Just to be clear, I have NOTHING against scalp tattooing in principle.
In my opinion, no-one should have agreed to give the guy in my picture a hairline like that.
There seems to be many cases of guys having other treatments to correct similar non-natural tattooed hairlines.

The picture you posted does look good and it confirmed what I thought looking at the site and exactly what Hairenough said, and thats it seems to work better on darker skins.
Hairenough also confirmed my other reservation which was that they can fade and alter colour over time.

Re the problems you've had re hair pieces and colour matching.
Did you buy a stock piece or have a custom one made?