I normally play the Standard Ernie Ball Regular Slinky Strings - but last year I bought a LTD ST-1 (which is my Main-Guitar now) and so I thought of testing some other strings. The Ernie Ball Cobalt Strings are packaged like the other Ernie Ball Strings - everything fine! After putting the strings on my guitar, the first audible thing was, that they sound clearer than the Regular Slinky. The Sound out of the Amp confirmed it very well. It's a very clear tone from clean to High-Gain. I think, they are a little bit more stiff - but that's no problem. They really sound great and open! But why just 4/5 Stars? Well, I think 1 big Star goes to the Mojo-Factor... I haven't tried them on my other guitars than the LTD - but as I wrote in the headline, I'm shure, it will give your Premium Guitar a little bit more comfortable playing.