If I wouldn't already had my NES collection in carved UGC's, I would definitely opt for these in the grey color. They look so pristine and the shiny outer sleeve is better than the shower windows style of the new UGC.
I may still buy a few ones to store the thick manuals -- Dragon Warrior 1-4 and Final Fantasy, etc...
There is just one issue I see with internal configuration: it prevents storing cartridge with the black dust sleeve - Yes, it's overkill, but I like it that way

If the bottom holder would be made symmetric to the top ones, with the side parts a bit longer to reach the widest part of the cartridge, it would allow storing cartridges in dust sleeve and still be secure when there is none.