As a Calgarian I must object

Depends what you like. Vancouver is a great cosmopolitan and large city with an impressive backdrop. Calgary is a mid-size city with an impressive backdrop. It is still a more mud on your boots (although some Calgarians don't like to admit it) grassroots, pretty friendly kind of place. In July you have the Calgary Stampede (unless you don't like to see the farm animals chased, wrestled and pushed to the limit in the rodeo) and some wide open spaces close by.

Vancouver takes a longer time to get out of to get somewhere wild so I suggest when going to Vancouver, stay there and enjoy the experience.

When in Calgary you will probably want to sample the city a bit and then get out of town. July is the time of year to do it.