Generally I find the St Lawrence market overpriced and overrated - you can find equal or better products all around Toronto; the benefit of getting all at one time is not worth the cost.
But Schleffer's has totally changed my view, because hot damn did they kill it this past Saturday. Loaded with free samples, ample sales staff who were more than willing to talk and let us taste their cheeses - without being pushy or stingy, and half price on all their french cheeses - we came away with some dynamite old cheddar and two bries. I will happily make the bike down here out of my way for all my future fromages.