I've always used Martin Phosphor Bronze, mainly, if not totally down to habit. I kept thinking I should try something different. I bought some of these, and some for electric, and so far they seem pretty good. They feel good, and they sound pretty good to my ears, and that's all I can really go on. The guitar I use the on ids a good, all solid woods acoustic, so it's probably going to sound decent, anyway, but I didn't hear any drop in the quality, with these strings on, as opposed to the others..