I only had trouble with quality once -- most of my layouts came back with a white border on one edge, or some text cut off on the edges, so I think someone forgot to quality check it. Anyway, I just sent them back for a reprint and they came back perfect. (They even called me when they received them, which was nice.)
They say they print to the edge, but there is some trimming, so be careful not to have anything too close to the edge. The guy I talked to said to leave 1/16" around each edge just to be safe.