I saw a 4115 today with a 72" MMM, 180 hours (dunno what year) and the dealer wanted $14900 for it. I might have jumped at it for $12k, with my 4100 as a trade. I did like that 72" deck, but i wonder how it would do on my sloping landscape? Anyone out there have any experience they are willing to share with a 72" MMM?