As stated above, the coated ones will last forever for occasional use. Some of my guitars sit for a year or so with the coated and they hold up. On the flip side, I was bragging about the coated strings to a friend of mine that plays out about 4 nights a week. The coated strings lasted about 3 weeks (versus his usual once a week changing) then the coating started flaking off so I don't think they'll hold up under extreme playing conditions. I recently tried the nickel bronze strings and was blown away with their initial sound bu they lost their sizzle after a couple weeks, but they still sound okay. I have a large stash of SP's so they'll do for now.