The thing to remember is if 1/2 of your system is plugged into a power conditioner, and there is a component plugged directly into the wall -- you are not protected from lightening on any of the components. You also have no warranty from the protection device manufacturer unless all of the connected components are connected to the conditioner.
BTW, I also have a Monster HTS2000 and I really haven't noticed enough of a difference to warrant not plugging into it vs. the wall outlet.
BTW, I also have a Monster HTS2000 and I really haven't noticed enough of a difference to warrant not plugging into it vs. the wall outlet.