Hey,
I rather enjoy my Pin*Bot, but I haven't played anywhere near all the Sys 11s, so I'm not overly in a position to say. With that said, Pin*Bot's a good solid game, nothing too elaborate, and other than the topper, relatively inexpensive to have kicking around. There's really something to be said for System 11s: they focused on fun without being overly elaborate. And I find that really nice every once in a while.
Luke