Whatever you choose, I'd look at their service performance level and their first attempt delivery rate, combined with flexible delivery options - options leaving at the address without signature/ parcel lockers/ where taken when not home/ time of delivery options.
You only have to walk down your street to know not to many Australians have kept up with the online shopping revolution in terms of the size of their letterbox so those flexible options are becoming more and more important when combined with a lot of residents not at home at time of delivery.
Probably worth asking sales reps how their companies do their hand overs between regions. Is it in a secure warehouse or in the gutter van to van - I see one second tier parcel delivery company lined up on the ovals on Vanessa St, Beverly Hills doing their afternoon hand overs. Certainly reduces cost if they take all the parcels with them or one of the drivers doesn't have a mechanical so is actually there for the handover.
No company is perfect but with barcodes they are all becoming a lot more transparent.