The 'Perfect Fit' easily slide into a normal 'Dragon Shield'. Here i need only a few seconds to doublesleeve my cards - not redoing the same card again and again with the KMC 'til they fit properly.
Differences KMC Perfect Fit / Dragon Shield Pefect Fit:
KMC PF: ~1mm taller, width is a tiny bit bigger, thicker material, totally flat, sometimes hard to remove cards from the sleeve - perfect for anything except 'Dragon Shield' outer sleeves.
DS PF : smaller than the KMC, thinner material, 'bumpy' when without a card, cards can be removed easily - perfect for 'Dragon Shield' outer sleeves, a bit loose in UP Eclipse, very good for other sleeves.
Now the material. The sleeves are made from a thinner and much smoother material in comparison to the KMC. But even if the material is thinner it is still more than enough to protect from dust or moisture (yep, had a minor accident). Besides your 60 cards double sleeved deck is now noticably slimmer and easier to shuffle.
In regards to the smoothness i can only say that i'm impressed. Cards slide easily into the 'Perfect Fit' and they slide easily into a normal sleeve. Same goes for removing a card or a 'Perfect Fit'.
With the KMC i often had to cut them up to remove the card. It was almost as if someone had glued them together (wasn't me!) and they were very hard to separate.
In the long run i'll get rid of the KMC in use and will get the Dragon Shield for all my cards (even the ones in the storage boxes).