But checking out the Canadian cellular towers map site, the SaskTel tower is much much closer to the border I went through than the MTS/Rogers towers, so that would likely explain it.
Man gets hit by Brick Phone! Ouch!
Use the various websites for "canadian cell tower map" to determine which carrier has towers closer to where you are.
I have access to both Rogers and Telus' HSPA networks through work. I've had time while working in the South Surrey/White Rock area to compare performance between the two. Every time I compare, I find Bell/Telus to be far better. Rogers HSPA coverage is like swiss cheese in the neighbourhoods of South Surrey and often roams onto AT&T. When you can get reception, the cell towers are often overloaded, making data connections slow.
Bell/Telus HSPA is completely different. Average latency is about 100ms even at rush hour. Rogers/Fido is all over the place between 100ms-1000ms.
Rogers really needs to boost their infrastructure out west. I get the feeling they're neglecting their HSPA+ network in favor of their LTE buildout.
At least Rogers/MTS HAVE a network in MB and it's not as bad as you're making it out to be.
I've been in the city during rush hour on many occasions and never had issues using my phone. The only time it's been sluggish is at Jets games in the MTS center and even then it was still usable.
Since you hate Rogers so much perhaps you should switch to Telus?