Gut has captured my heart. This is effortless tennis with feel and loud cracking shotgun sounds. I think this is the best Head frame I have ever used personally and I owned some pretty sweet Head frames over the years, my favorite being the Graphite Master and the PC600. There is a simple joy and feel to hitting with gut, whereas poly is just a soul less and heartless string IMO. I still appreciate poly of course; it just always felt like dancing with the devil.