I thought about going top of the line, but from the reviews you get better performance, but not by a huge margin. The ST series is pretty fantastic and I plan to get a 65" version of that line. I still want to see the ZT series in person before I buy just in case. It is a fantastic looking TV, but for the money I save getting a cheaper model I can buy a new projector that will blow away what I have. That to me is worth spending less on the tv.
Have you seen a ZT in person yet?