I do maintain that there are quality variations - how could there not be?
The 4000s Plossls must have been made under very strict quality control at one time. If the spacing between the elements is not perfect, the field stop will be fuzzy, or even blue-fringed. The no-names are highly variable. They are likely 2nds that work, but are not of minimum standard for some sellers. Meade always got the best out of their optical partners. I have seen many 4000s other than my own set and they are uniformly excellent in both construction and performance.
I would expect that GSO use similar quality standards. Those are surely good eyepieces.
-drl
I have the 32,25&9mm GSO plossl EP's for my CC6. They are nice and the views are awesome. I bought GSO superviews 20&15mm for the same scope. Love the views. I will probably buy the 20,15,12mm plossl from GSO as well. 52° in those are nice.