Well... They seem to have chosen only the Motif's "Full Grand", the old CF3 sample... They should have compared with the newer S6 piano, too, to have a meaningful comparison.
Nevertheless, even if the Motif 'Full Grand' sounds better here than I remember it (I only use my MoXF Full Grand in a band context), I think the Roland SN-A pianos are considerably better, also better than the S6, which isn't 88-note sampled.
But as soon as you install one of the top piano library options onto the Motif flash board, that piano might win against the SN-A...