Fast growing cities are Yo-Yos...  Las Vegas was the fasting growing U.S. city in the late-90s, only to go bust. In 2007 Las Vega's housing crashed harder than most cities, and their population declined through 2010. Now it's picked up again, but it's very volatile. Meanwhile, New York has experienced slow but steady growth that is far more reliable.

Same in Canada. Toronto, Montreal, and Vancouver are not the fasting growing, but they're going to be much more stable than one-industry prairie cities.