years of use? wind passing through? seasons to use?
I would bet that cuben is attacked by UV light (someone please confirm or deny this belief) so years of life might depend on how much you use it=I wouldn't leave it set up unused outside for lengthy amounts of time.
Wind passing through? There is a test that tells at what p.s.i. water will penetrate a given subrate. Again I'd like a professional answer but cuben by its nature has got to be far better at water (or wind) penetration than nylon even when coated with silicon.
Seasons to use? I use cuben (in sock form) year around now. It is the go-to fabric; but I used to say that about other materials over the years, materials that are now in the history books.