With built in book cases it may be best to put the receptacle in the toe kick but that requires coordination between the cabinet builder and the electrician. On Harold's big entertainment center, where is that floor to ceiling TV plugged in?
I would want a quad in an entertainment center and you still may end up with a quasi legal plug strip. It is probably beyond the scope of what they pay for but the user would want a lot of stuff behind his entertainment center if he could get it (in wall chases for cables etc). You certainly want plenty of places to plug things in.
