Warning: sleeved my whole gloomhaven set before checking one thing, now I'm out $70 and 6 hours
I sleeved all 1,800 cards in Gloomhaven with penny sleeves first, then a guy at my FLGS in Portland watched me shuffle and said premium sleeves would've cost the same per pack on sale and shuffle way better. Now half my deck feels like a wet noodle and I'm redoing the whole thing before our Saturday campaign. Has anyone actually compared penny vs premium on a big campaign game without wanting to cry?
A guy at an FLGS told me the same thing once, that the shuffle feel alone makes premium worth it on games where you shuffle constantly. I read a BGG thread a while back where people measured it out and said penny sleeves stick together more and get air pockets, which is why they feel like a wet noodle, exactly like you said. For a campaign game where the cards hit the table every single session, that adds up fast. Sucks that you already did 1,800 of them though. If it helps, the redo goes quicker the second time since you already know the drill.