I also tried A-Z mount quite some time ago with good results, see
here.
The scope I used (10" Newt, bartelized dob mount) will one night be on EQ6, but until then, I intend to use it as is for AP.
Since the bartels system supports field rotator, I will try to put something together soon, for longer exposures....
Also, field rotation is not the same across the sky, it is minimal (zero) for azimut 90° and 270°.. see
here.