fa35/a7r, probably 10 vertical shots stitched in photoshop, the final tiff was over a gig... a staggering amount of detail... shot off of a monopod, using a bracket that was close to rotating on the nodal point.
i always do vertical stitches, because the sides of a lens is weaker than the top/bottom, so the stitch works better using sharper parts of the image to make the match with.
hand-held works well, using the level indicator to reference the horizon line, and to reference the vertical axis... live view in a dslr lcd, should have a level indicator?