The less than stellar reviews I read on the 64st came from Amazon.
While I know enough to take all reviews with a grain of salt, my 60CSx works just fine and my desire for a new unit is based on want, not need.
Based on the way I use my 60CSx, what intrigues me most about the newer units is a larger display, more characters permitted for waypoint names and more custom waypoint symbols. Since I already know the 680t has all three, if I can expect as good reception, accuracy and features, there may be a 680t in my immediate future once some reviews become available.
Thanks for your input!