I am in the market for a Z-Track. I have decided on a JD in either the 727 or the 737. I don't want anything bigger than the 54" deck. Is there that much difference in the trim capabilities between the two and how important is it? The mower will be mostly for personal use, my yard, my parents, and two ot her yards. I have seen the 7-Iron II with the Mulch on Demand and really like it. Will JD make a kit to attach it to the 7 Iron II decks that don't have it? If they will I would go ahead and get the mower and attach the MOD later. Also I have seen the new Dump from the Seat System in a brochure. Will this system fit on a 727 as well as a 737? That would aslo help with my decision. Thanks for the help!