MC phono cartridge lifespan (when not using)

The concern with shelf life has to do with the "rubber" suspension parts.  Some of these can change in characteristics with age.  That tendency increases with the level of pollutants, particularly ozone.  If I planned to keep a cartridge for a while, I would consider sealing it in an air-tight container.

That said, I know of a lot of people using 20-30 year old cartridges that are perfectly fine.  Koetsu, as a brand, comes to mind.  Another brand, Allaerte specifically touts, as a feature of their cartridges, the use of suspension elastomers that are well more than a hundred years old so that their characteristics are now quite stable.  I don't know about Benz specifically, but then again, I have not heard anything about their cartridges going prematurely bad, so I bet they can be held for quite some time.

Put it in a jar with a screw cap lid and keep in a cool, dark place - like vitamins!

The glider is a great cartridge.  Give it a try!

Yes .....to put my Glider in a jar is a great idea and should keep it fresh for many years.....and being that it is a great cartridge, I think I should keep it for when my Wood is worn or out for service....Maybe in 5 years these Glider won't be available or non affordable.

Would you people sell it or keep it....?????

I generally have had great luck with aged vintage cartridges, particularly MM and MI types.  But one could argue that I have no idea how those same cartridges sounded when they were brand new.  Nor are my ears and brain in the same shape they were in 30 years ago and more.  Nor do I have the same equipment I had back then; better stuff now.  I have two cartridges that I bought new, a Koetsu Urushi, now about 8 years old, and a Grado TLZ, now probably more than 30 years old.  I think both have lost a step or two or three over the years, but is that due to ordinary wear due to heavy use or to aging per se?  Quien sabe?

PS. I don't want to rain on anyone's parade, but I think the Glider is mediocre at best.  I have owned two and still have the second one I bought.  It would be on the bottom of my list of all cartridges I use now, if I used it at all, which I don't.  In general, I have not liked HOMC cartridges nearly as much as LOMC and MM/MI types. I have another HOMC, a Transfiguration Esprit, which I found to be superior to the Glider in all ways but still not up to my LOMC and MM/MI favorites.