I bought a pair.... icp and ipr with pig tails.... off ebay just to have some on hand.
Long story short they sat a long time and I finally needed them. Pulled the ones off my bus and they were original ( 2001 model) so I was a bit shocked. I had a crank no start situation so we changed them and it fired right up.
Been running a week or so now with no issues.
I am about to order another set as a back up. Figured if I only get a little bit from them (hopefully longer) that I can swap them again and hopefully stay up if I have problems.