I'm Canadian and worked in high-tech in Ottawa, Toronto and Vancouver until 2006. Then I moved to Southern California and worked there until 2010 (on a work visa) and have been in Australia since.
In Ottawa I worked for the federal government. It paid off my student debt but professionally was a dead end (although that's mostly true of any government town). I then worked for a branch office of an American company in Toronto (although FWIW most of the developers were Romanian) before moving to Vancouver where the startup I worked for folded in the aftermath of the dot-com bust.
I loved living in California but hated the restrictions of the H1B work visa so moved to Australia (my wife is Aussie) largely so I create my own startup, which I've done (https://www.SlickDNS.com). The weather in particular in California is fantastic.
The fact of the matter is that compared to the US the high-tech economy in Canada is very small. There are really only a handful of cities with a high-tech sector (Montreal, Toronto, Ottawa, Calgary?, Vancouver) whereas the US has at least as many regions with sizeable high-tech sectors (Seattle, Silicon Valley, SoCal, Texas, Research Triangle, Boston, NYC).
In all of the cities in Canada, the weather is worse, salaries are lower, taxes are higher, and houses cost more than pretty much any of the US regions I mentioned barring perhaps SF or NYC. (Vancouver's real estate is notably expensive, largely because it's an easy way for nominal immigrants from Hong Kong to park their money.) So financially the US is unbeatable, but the price you pay is having to put up with the Kafkaesque US immigration system and work visa restrictions.
Australia's economy is actually quite similar to Canada's in that it's dominated by the natural resources sector. House prices are also similarly in a bubble (e.g., try comparing prices for 3 bedroom houses in Melbourne vs. Austin), but on the plus side the weather down here is better. I do miss Tim Hortons though.