The problem associated with the non-standard level debate is that unfortunately they are sometimes required to facilitate an expeditious flow of traffic. During the night over central australia there can sometimes be up to 30+ aircraft in a congo line heading to YSSY/YBBN/YMML... Without non-standard levels we would have people cruising at FL280 ect ect... However it must be said that whenever a controller assigns a clearance then seperation becomes HIS/HER responsibility. We can say we are all pissed off/fatigued ect ect but once we plug in and assume control then we are bound by law/duty to perform our role.