i've been dealing private games on / off for 20+ years.... i've tried A LOT of different cards over that time span
for me, when all factors are weighed, copags are the best
i see ABSOLUTELY no reason why a new deck should not be used for each new session of play.... i ALWAYS bring a new deck to gigs i deal... when you buy copags in bulk, it comes out to around $12 per setup.... if you're making decent money in tips or running a raked game, you have no excuse (except being cheap) to not break out a fresh deck for each new game
and if you're running a friendly game: have each player chip in a buck for a new setup each session... i TOTALLY would as a player
after even ONE session a setup can get completely whored out from gunk and moisture from players' hands etc.... not to mention thumbnail imprints in the cards, etc
i do realize that there are tougher cards out there... but have you ever tried to deal a 8 or 12 hour session with modiano's? it's fuggin BRUTAL! may as well use roofing shingles... they're way to stiff and unforgiving
kems are nice, but just too expensive to swap in a new setup each session
i'm completely content with copags... i never use anything else