That's such a difficult question to answer. I think Rogers' plans are among the best ones out there right now. However, every provider seems to have little niches where they shine.
Additionally, in Saskatchewan, SaskTel's coverage footprint is significantly larger than Rogers'. Rogers' isn't bad - it covers all the cities (except Humboldt), and the major highways between them - but it could be better. For example, Waskesiu has no coverage.
I use Rogers and my solution to the coverage issue was to get a prepaid phone on Virgin Mobile to use when I'm outside the coverage area (which is, admittedly, infrequent).
Look carefully at the coverage map. Ask friends who use Rogers. Look carefully at the plans and make sure they make sense for you.
Rogers' big advantage is flexibility in hardware (since they are a GSM provider you can use any compatible phone you like, as long as it's unlocked or locked to Rogers). SaskTel's big advantage here is their service area.