I got a set of size 4 DPNS November 2012. So I've had them now for about 8 months. I originally purchased the set to test them out. I want to replace my wooden 0-4 needles because I'm afraid I'm going to snap them. This seemed like a great replacement, Carbon fibers with steel tips. Kind of neat! The tips are nice and sharp and consistent unlike wooden needles but The join where the carbon meets the steel tip is not flush. For thicker yarns this isn't much of an issue, but for finer yarns it catches easily. Since I'm a loose knitter, I wasn't worried about it and just resolved to use my size 4s on worsted/dk weight projects. Recently, one of the steel tips has started to come loose. It hasn't come off, but I can see that it's probably not far from doing so. I'm a little disappointed in these, I had high hopes. I'm glad that I tried out a set before committing to purchasing multiple sets.
Even though I have the addi click set, I want to start collection these. I like these because they are light weight, have a feel that is not slippery. I have circular ones that are great, the cords dont fight you while you knit.