It looks like PSE doesn't have too many fans here.
And I'm not surprised.
The way I understand it PSE which stands for Professional Stamp
Experts grades stamps by comparing
them to known copies and assigns them a number (please correct me if I'm wrong)
Apparently they also do expertizing but here they seem to have problems even getting the Scott numbers right for some
classic US stamps.
But from what I can see all their "grading" is about
centering never mind for instance how lousy the perforations look.
This is the stamp in question as mentioned in my first post.
Just look at the perforations, bottom especially.
For a modern stamp they look plain awful.

Who really cares whether its centered to the 1 one thousandth of a milliliter or to 1 one hundredth.
My eye knows if the centering of a stamp is up to my standards,
I don't need some so called "experts" like PSE
This whole thing reminds me of the premiss of the the Seinfeld TV
series which was that the show was
about nothing.
Well this grading racket is trying to make something out of
nothing.