From an instructor's point of view I teach my students when on navexes to use the frequency that will give them the best situational awareness of other aircraft in their vicinity.
When you are bimbling along VFR at 3500 I don't see how listening to ATC giving IFR clearances to RPT at flight levels is going to achieve this.
The only time that Centre (are they called Area now?) frequency is of any use to us is if we have a flight plan/SARtime amendment or a mayday. Trying to get their attention can sometimes take up to ten minutes if they are busy doing their real job.
Where is the safety improvement if Farmer Joe departs Woop Woop Station talking on Melbourne Centre and we are on 126.7 in the vicinity? How is him knowing that Qantas are at FL350 going to improve safety?
Personally I think Centre should be used for IFR and if we VFR need to talk to someone for assistance, relevant CTAF for everything else.
IN real life though the chances of it actually making a difference to safety are very small. It also shows that the CAAPs have limited or no legal status (Am I right Creampuff?) and you must always refer to the AIP.