I finally tried some 4G (17g) hybrid with Classic gut today. I found it to be okay. For me, it isn't as good as the gut/Tour Bite hybrid I have been playing. It doesn't spin as well or feel as good. Don't get me wrong, it is a fine setup, and probably better than the gut/Hurricane Feel setup I had been playing, although the Hurricane Feel setup has set the standard for longevity in my gut/poly hybrid.
It's not a bad string for me, just not as good as some others.