<font color=blue>I would not purchase the 54 inch MMM.</font color=blue>
Tres, two reasons for the 54 incher. First, I've been known to mow my entire yard (such as it is) with a Ryobi string trimmer and less than two tanks of gas. Obviously, I'm planning on more yard and more effort to mow (I do it currently maybe three times a year).
Second, and more important - the shed I'm planning on keeping the tractor in (when I finally get the ramp built next week) has a 60 inch doorway. If I lift up the discharge chute flap, the 54 inch will fit; the 60 inch is 63 (or 65 -- going from memory) inches minimum size.
Tom