I never had any issues with any headset on any of my bikes. And I rode some cheap bikes throughout my life. Other than a few of the old threaded headsets that were just a tad different in the way they were supposed to be adjusted than the others.

And I really find it hard to believe that some can tell the difference between them for just the very few degrees it's moved while actually riding a bike.

Or is all the difference in perception of the headsets just when turned by hand in the work stand?