I'm getting back into my arco studies and could use some string perspective from the group. I recently had a set of Obligatos on my bass, which had a gorgeous arco sound but didn't have quite enough pizz for me. I took them off and put on the Helicore Hybrids that came on the bass when I bought it, and those have nice punch, and I can get a decent arco sound, except up in thumb position where they're terribly scratchy. What about BobG's favorite, the Corelli 370s? Has anyone compared these to the Hybrids for arco sound?