So I finally got to play both. First time. I played gb, then th then gb then th. A few games each time. I've never gotten into a pinside flame war and I don't intend to now. But to me, there was no contest. Gb seemed like a child's toy. Admittedly, the shots were smooth and fun, but it just felt cheap. Th also had great flowy shots but felt solid. Art was different (and to my eyes better) on th.
My biases do include the fact that I don't own any sterns. I have mostly Williams/Bally pins, desw and woz. I've always thought desw felt cheap (though I love it anyway). So to me, th seemed like the successor to this lineup.