If you want to play Blues - Rock n Roll, these are the right strings because they don't have a "polished" sound, but a Vintage feel.
Very good durability, especially if you wipe the fretboard with a cloth after playing so that no residues remain.

D-Standard tuning, on a 25 1/2" scale, convenient set. Loose/soft, but they hold the tuning. I haven't played with the regular Slinky (I play with Cobalt) for years (maybe even a decade), and when I wanted to play rock again, I went completely to the opposite side. So I don't know if the sound change from the regular Slinky to these ones is dramatic.