Two years ago, I had a Blackberry with WIND mobile. To be honest, the reception I got at McMaster was poor. Regardless of where I was (basements/outside/lecture rooms/etc.), my calls got dropped a lot and text messages would take a while to be sent. However, this was two years ago and after a year I quickly signed up for a plan with Fido (I now have an iPhone, and I get much better reception at McMaster with Fido). I know that WIND's coverage was supposed to improve, but I just couldn't wait around for that, so I can't really say how it would be now.
Long story short, I can't really offer a comparison between the other carriers you mentioned, but, switching from WIND to Fido was a very good decision for me in terms of price and reception
