I use it on a Kaiser 6x6 and it works also in manual mode with my Durst Laborator 138S. It is right, you have a good first workprint without any test strips. But it is still you who has to interpret the negative. I use it with great success for lith printing, where I get a very good guess about the exposure time from the measured exposure time and the measured paper grade.

Cheers
Ruediger