In reply to bodovix:
My 12mm dyneema mix slings lasted many years of frequent use and pull tested to a perfectly adequate strength once they were retired (I don't recall specific numbers but I wasn't surprised or alarmed). They were pretty shabby looking when I retired them. I currently have a mix of 6, 8, 10 and 12mm slings in my rack, the main difference seems to be the nylon fraction. I can't say I worry about the lifespan of the thinner slings, they seem to be faring fine but it's not the sort of thing that preys on my mind anyway.
My suggestion would be don't worry about it, they'll have long since paid for themselves in many happy days out by the time you feel the need to replace them.
jk
Post edited at 11:39