Well, I am a machine quilter and the little 'hump' doesn't bother me when I put the ditch seams to one side. Something about feeling in the middle of the night the pattern that you worked on, even though you can't see it. I am more concerned with keeping the pattern straight when doing small piecings.
It does seem like the joint is stronger if the fabric goes over to one side and you quilt along that edge.
tim in san jose