From the cases I've looked at, there's not a tremendous amount of jurisprudence on the issue, so you might not be the only one who's still trying to figure it out.
You're correct that suspicion is certainly a lower standard than belief. As for how that standard differs, it's not a perfect scientific exercise. There was a comment in a recent Supreme Court of Canada case, I think, from Justice Binnie, in one of the drug dog cases--I think it was Kang-Brown--where he fleshes it out a bit, and suspicion is something less than a belief.