Is it better to use Click and Send or continue with Australia Post account and lodging at Post Offic

Is it better to use Click and Send or continue with my Australia Post Account and lodge items at Post Office.  Also I haven't been able to find where to get sticky labels to attach to parcels.  I don't trust just taping a bit of A4 with the address on it to the front of the parcel in case it gets dislodged.