I got these strings because I generally go through a set of Ernie Ball Power Slinky (11-48) strings every three to four gigs before they sound muffled and lose their twang.
These are coated strings which means there is a very very thin covering around the string which is supposed to stop dirt and muck from sweat and dead skin from getting into the windings of the strings which is what deadens them. They feel different from normal strings in that they feel slightly "slippery" compared with the uncoated ones.
However, after playing them regularly for a couple of weeks I have to say that I'm surprised at how fresh they still sound. I'm impressed and will try them on my other instruments to see if they keep the same feeling.