I have tried several, in fact I have a set of squeaking Mintex on my wifes car that I need to change out for some Jurids this weekend. I know better than to use Mintex, axxis etc but I had a set I got as a sample so I tried it. Complete garbage, the pads are not tapered, there is no shim, no vent cut and they are painted with paint that burns off in a couple stops.
TUV is a very important specification for braking systems and traction control. Changing braking characteristics will change how the vehicle performs when the ABS and traction control systems are activated. If an unapproved pad is used all bets are off with both those systems.
Check out
http://tuvamerica.com/newhome.cfm when you have time, it's not some empty ISO certification, it's much more.