I have a 4710 with R4 tires, 460 FEL and ballasted in the back with about 1200 lbs. When it's wet, I can make some pretty good ruts in the clay we have around here. But don't let that stop you. It's a great tractor - especially with the hydro transmission. I took the loader off the other day to work with a landscape rake in and around some pretty thick trees. Without the loader, it turns and handles great. I don't have a MMM, but if you had one, you could get around trees pretty well with it. I don't know what turf tires would do to the equation. From what I've seen, they are much wider, and may inhibit the turning radius and agility.
One thing to consider is its height. The larger frame puts you up in the air more - making problems with low branches. I had to go around and trim all the low branches on my property before I could get around very well under trees. And I still have more to do. On 14 acres of pretty dense trees, that's a lot of work.
Hope that helps.
J.