They have only been om my vin for a week, so I cannot say anything about the life of the string, but being Kevlar (used for bullet proof vests) and other high load uses, I suspect they will have a very good life.

With these strings, the resonance sounds clear and the life lasts longer than comparable priced strings on my violin

The E is nice, but is a bit "tinny" (not surprising since it's plain steel) which has taken me a little while to get used to.

The longer I play with it the better it gets, but I may end up experimenting a bit more to find my perfect E string.