Ultex picks sound a bit jangly on my Martin dread so I use something else, but these babies really brought my Gibson jumbo to life like nothing else did. I had tried everything to coax an exciting sound out of that big old box, but these picks finally did it. They were a total revelation: bright, crisp, clean, upfront sound. Easy to hold, fast and slick, they feel good against the strings and boy, do they sing. I use the 73's for flatpicking or digging into blues, and the 60's are great for smoother rhythm playing. Sometimes in a pinch I'll even use a 1.0 on the mandolin, although it's not my first pick, so to speak. Contrary to other reviews citing indestructibility, I have found they do create dust from being shaved against the strings, which is a little strange and a just a tad messy, but it's more than worth it for the sound. My only gripe at this writing: how come the 60's run a buck-fifty more per six pack than the 73's do?  Oh, the injustice.