It is a personal preference. My own preference is definately Calphalon. Circulon’s ridges hinder the nonstick-ness to my experience, and make it slightly more difficult to wipe out. Calphalon’s nonstick, handled properly, is a better product, and is better rated. For two products in the same price range, I’d go with Calphalon.
Before buying either, check out Scanpan. They make by far the best than most of the cookware out there. Be warned Scanpan cookware is expensive BUT will last you a lifetime with minimal care. We have 2 Woks by Scanpan and I cannot praise them enough.
price and quality. Buy one piece of each and decide for yourself.