I've been playing these on my bass for a couple of weeks now. Very cool, indeed. Very, very dark, pizz but the sound also seems to be quite clear. With the Stick, they're fabulous. Coming from Spiros I find that there are certain things that I can't do pizz that I did before, but the difference in sound makes you play differently, anyhow, so I don't miss what I'm missing -- if that makes any sense. At first they seem to be markedly softer in volume than the Spiros, but what remains when you forget about all of the high end and mid of the Spiros is great, strong fundamental. Also, after a few gigs and sessions, you figure out how to get a number of different effects (pizz), covering the gamut of dynamics and timbres. This all seems to carry into the room quite well, and maybe even betters than the Spiros, which can mush out acoustically in a room once the mids and highs have fallen off over distance. You have to have someone else play your bass to really appreciate the difference, I think. These are pretty famous orchestral straings, so I don't need to go on too much about them as far as The Stick, other than to say that it's really refreshing to spend energy and focus on getting aspects of the sound that you want instead of tip-toeing around aspects of the sound that you don't want. Currently I'm running a Spirocore E with the set, but will soon be trying the Stark Flex E to see how that goes. The Spiro E has it's nice properties with the set, but sounds a little thin next to the other three.