Currently I am using two ’long stored’ cartridges, and surprisingly, they both sound great.
Played a few hours for a few days, then started listening critically. I assumed the rubber/whatever the cantilever passed thru would be dried out/hardened/inflexible. Perhaps oxidation of internals.
My MM, AT440ML, very lightly used, stored loose in a baggie in a drawer since Shure V15VxMR came out around 2003/2004. I had to use several spritzes of brake cleaner to get the aluminum cantilever clean. Luckily the tip was not glued on. I figured, it’ll work or it wont. Damn thing sounds great.
Friend’s New, never played MC, Goldring Eroica LX, new in box in the drawer for many years. Luckily it looked clean under microscope, I wouldn’t spritz someone else’s cartridge. Same thing, play a few hours a few days, then start listening for real. It sounds very much like my new MC AT33PTG/II. Perhaps differences, but I don’t want to wear it out. He listens to it here until he gets a SUT.
I will say, same LP’s, the Eroica’s Gyger II Stylus tip tends to hold onto junk more than any stylus tip I ever owned. I need to clean it every play. My other’s, SAS and ML might only get a speck of dust playing a/the same clean LP previously. I think the shape front to back must have surfaces closer to the edge that the ML profile, i.e. something to stick to rather than to fall away from.