What is the shelf life of fluorocarbon line when stored properly in a cool, dark, dry place?

My guess....longer than anyone would live to be concerned about.

I've heard a few people say it can get brittle after a couple years of sitting on the shelf. Has anybody experienced this? I'm considering buying a bulk spool.

I am using BPS floro two years old with no problems.

The only time I have had trouble with line is when it is stored somwhere it should not be. Ex. in the sun, in a hot boat. Etc. I keep all of my line in the basement of my house and have never had any problems with it, it stays about 65 degrees down there year round and does not have any windows. I have some line that at least 5 or 6 years old that is still good.