My perspective from living 20 years in Melbourne and 12 in Toronto:
The short story: Toronto is bigger and busier and has better “city living”, Melbourne is more relaxed and better for being outdoors.
– Toronto has four distinct seasons, with periods of way-too-cold and way-too-hot (humid), Melbourne is mostly pretty nice all year.
-Toronto is significantly bigger, and in a highly populated province and part of the continent. This is great for having clubs/communities/companies catering to whatever your interests may be, but worse for getting away from the hustle and bustle.
– Toronto is more multicultural. Melbourne is mainly a mix of European and Asian, while Toronto more evenly covers the world’s nationalities, and has easily-accessed communities of many of them (your Little India’s and Chinatown’s and so forth).
– For playing sports, Melbourne is better for every summer/water sport. Toronto has a few months of ok weather for all sports each year. For watching sports, Melbourne has Aussie Rules and cricket, and some rugby and soccer, as well as the Australian Open, Grand Prix and Moto GP, while Toronto has NBA, MLB, NHL, CFL, and whatever the national lacrosse league is called.
– Toronto has better fine dining and more ethnic options; Melbourne has better quality food otherwise. Melbourne also has better coffee.
– Better music and art scenes in Toronto.
– More relaxed and friendly in Melbourne, while it’s higher energy and career-focused in Toronto.
– Driving is more necessary but easier in Melbourne. In Toronto, traffic is generally terrible, and occasionally horrendous during snow, freezing rain, etc, but if you live in the inner-city, owning a car is not necessary.
– Canadians are more polite and politically correct, Australians shoot from the hip.
Lastly (and somewhat tongue-in-cheek) if you live in Toronto, people in all other Canadian cities will despise you, and you will only acknowledge them when you travel there for holidays. Melbourne is one of the two biggest cities in the country, and better than Sydney in most ways, but will never be recognised as such. 🙂