First. I normally play Ernie's slinky 10?s. I've played Cobalt for a month know (couple of hours/day) , and they still have the clarity and "shimmy". There?s a different kind of tone compared to normal Ernie?s for shure. Not shure if it is for everyone, but me likey. If the price was around 7-8 € would be even better. Even if you, as I, have never really been a nerd about special coted strings, I strongly recommend to try these.