tube amplifier auto bias- accurate?


Hi I am new to tubes and this hobby, I read somewhere autobiasing is a gimmick, I was wondering how accurate it is. Is it possible it could be inaccurate? Is there a way to test its accuracy. Also what tube tester is good for beginner.
samuellaudio
I have an autobiasing tube amp (Primaluna) and it sounds fantastic. I'm all for this "gimmick". Sorry, all I can give you here is my opinion.
I have had two tube amps with auto bias, I have no reason to believe it didn't work- the sound was always fantastic.
Most auto control processes are as good or better than you can do manually. This would obviously be a requirement on the designer.

In airplanes, even little ones, the autopilot flies the plane more accurately than a pilot. This is hard for macho pilots (like me) to accept, but fuel consumption on a long trip proves the point.