Useful Life of a HSS Life Line?

[Mint]

I bought a few of the HSS Life Lines a couple of years ago and in their instructions they say they are good for a two years and then should be replaced. I only leave mine out for the season which is Oct - Dec 31. Do you still think they ok? What about the Safe Tree Hunting Systems since they use Blue Water rope? I think I am going to go withthem since they look like a much better quality of rope.