I've used Balo in the past. Pretty much on BMWs. On the 7 series, which is a heavy car, warped rotors are common. Going to Balo typically solves the problem.
They are made in Germany in their own foundry and precision machined and balanced...all done in house.
For the money they're excellent rotors.
'85 380 SL (sold)
'85 Carrera Flatnose
'71 280 SL Signal Red/Cognac