Good Morning Bass Lovers. I currently use DR Sumbeams and like them. I am finding they seem to lose their stiffness after a couple of weeks. The tone is pretty darn good after that time though. I hear a lot of good things about the Tomastik Power Bass strings and I'm wondering how they compare in Stiffness to the Sumbeams ?? I wouldn't want anything floppier than the DR's already are. I don't know if it's the round core on the Sumbeams or what. I play mostly finger style.