I am sadly having second thoughts about the Pirastro Permanents I recently installed. Well specifically there are two things - one is the very slight drop in volume from the Dominant A and Spiro C extension, the other is the lack of fundamental below low E for pizzicato. Other than that, the strings are very nice - warm tone, good response with the bow, and a nice pizz punch. They have a bit more damping in them than I expected. On the positive side the shorter sustain matches better with the gut strings on the top. However I think it's also what is responsible for the two complaints I have. Ironically, I keep coming back to the Spirocore C extension string. That string is bright as hell and not all that great with the bow but it does have a lot of volume and has a strong fundamental pizz or arco all the way down to C. If I use the Spiro then I'm also presented with the problem of what to use as an A string that matches the gut and transitions to a brighter bottom string. The Dominant A was OK although a bit bright and the thought of breakage scares me especially since I've taken it off and on a couple of times (and I got it used). I do have a Superflexible A lying around and am thinking about trying a Superflexible C extension. Also there are Jazzers. Can anybody comment on the Jazzers vs Superflexibles? I believe the latter are easier to bow?