NetOp alternatives_lab or classroom controllers

I've been having success with NetOp in my labs. Rather than rubbernecking to a SmartBoard, I simply take control of the kids' monitors to demo tricks and bells and whistles. We named the system Finkelstein after a great Rabbi, we are a Jewish day school. I can also spy on the kids while they are working without their knowledge which is very handy with middle school girls to prevent a lotta facebooking and chat rooms when they are supposed to be PowerPointing. NetOp is okay but I think there must be better lab controllers out there. It also conflicts with Deep Freeze so we had to turn that off. NetOp also lets you "pass the chalk" to a kid who is really savvy with some function and he or she can take over the class briefly...they live for that! But I am ready to upgrade to a better one. Any ideas out there????