I've switched between Shaw/Telus while in Calgary a number of times, I found like everyone else knows that Shaw's performance was greatly dependent on your area, and how much they had oversold/underupgraded their network/whatever, while Telus' performance always seemed "as advertised" no matter where in the city I lived. Telus it came down to $$ while Shaw it was always how, and "if" it worked decently enough for me to not go mental.
While stuck in the 7th circle of hades (Saskatchewan), there is only 2 options really as well, Shaw (now Rogers, FUCKFUCKINGFUCKFUCKFUCK), and Sasktel. Sasktel would be hilariously overpriced compared to Shaw/Rogers, however I have a close relative that's a VP with Sasktel, who is able to hooketh the $$. I've had both, Shawgers 1gbit connection has been amazingly stable and solid for years now, as were all the previously service speeds prior to 1gbit being available. Sasktel's fiber is fantastic, no usage limits/caps, very solid speed, and the $ I pay is basically the same as the Shawgers deal we have for another year.
Sasktel's Infinite fiber has 500mbps upload, while Shawgers 1gbit plan has some gay upload speed, I can't recall offhand what it is exactly, but it sucks.
If I could have just one I'd stick with Sasktel, especially after the PITA of them digging up my back yard and putting in a plastic tube from the alley in order to run the 2 fiber cables they needed to run. Plus the upload speed, not that I upload all that much any longer.