Personally I prefer SYD over MEL.
1) Far better shopping/dining airside services, both T1 & T3 at SYD. MEL landside offerings hardly exist.
2) MEL awful oversize luggage drop off, eg. check in then need to walk all through the check in area to get to the luggage drop off in the back corner fighting through the JQ/VA/TT pax waiting to check in.
3) split level for domestic makes going from check in and security/lounges to departure gates troublesome, with wheelchairs or prams difficult the couple of lifts are out of the way and slow
4) international arrives passenger journey not efficient and too few biosecurity lanes
5) terminal space too dark, low ceilings not conducive to a welcoming ambience
Sure SYD means you need to wait for the bus, I do not mind the trip across the airport solely due to close look at aircraft but it is a decent break from being in an aircraft/airport for hours.
When I did my MBA I studied one of the LON airports and their view of the customer experience. In summary, customers hate waiting in lines, better for them to have spare time to purchase goods at the airport, eg food or other goods. Airport did not charge rent for the shops, instead they received a % of the takings so therefore the airport was interested in a shop mix that had a high $ sale per metre. Even popular shops were encouraged to broaden their offerings and to ensure people were not waiting long at counters. People going on holidays do spend money buying things at the airport even though they could get the same thing at their regular shops eg. clothes, jewellery, they just were in some sort of mind space that reduce their wallet constraints that they normally had.
Regarding smoking areas, when I was backpacking I smoked the most. Hated FRA but laugh at their smoking areas and how dense the smoke, as opposed the comfortble areas at MUC. Best was in PNH where there was a very comfortable lougne, equivalent chairs to Qantas lounges. and even had BAT girls give me cigarettes to smoke while in there:shock:
Of course not smoking now so immaterial to me.