I have three P-Basses. i string each one with different strings so i can alternate playing. I have roto steels on one, fender flats on another, and ernie ball nickels on the third. I always end up playing the one with flats. I cannot seem to get a good sound. I tried all roundwound strings (fender, daddario, EB, DM etc etc) and i never satisfied with the sound. I strung them all back to flats and will just change basses depending on the mood i'm in!