My first experience with Gerstlauer trains was less than pleasant. The Boss at SFSTL left me bruised and badly hurting, especially in the left leg and my back. I thought that they tracked poorly and that the lapbars were designed by satan himself.
But then, earlier this summer, I visited Holiday World and rode the Legend. The Legend was incredible in nearly every aspect, and I had no trouble with the G-trains at all. They tracked smoothly, and while my leg bumped the bar, it never was driven into it and bruised. This leads me to think that the problems I experienced at SFSTL were caused by the Boss itself, and not the trains. I haven't ridden the Boss this year, so I don't know if improvements have been made. I do know that on each of the four rides I took last year, the whole train shouted ouch (or expletives) on that damned right turn after the double dip.
Perhaps the new lapbars, or some of the offseason improvements to the Boss have made it better. I still kind of like the PTC's better, but the G-trains did load easier and look nicer. I'm still waiting to try out the Flyers, but they look sensational.