I have a 2015HST which is basically the same as the 2216HST. Have you ever thought of buying a 3 point finish mower for the rear instead of the MMM? I can put on and take off my Woods finish mower in just a few minutes with no tools and no need to get under the tractor and no hydraulic lines to mess with. The only reason why I would ever consider a MMM is if I were going to cut grass with the loader off or use in tight spaces, again with the loader off. My 2015 doesn't have a turning radius like a garden tractor so if you have a lot of trees to go around, you might be happy with the MMM unless the trees are close together.
If you are cutting a wide open space, then why not price out a rear mower. I bet it would be cheaper than the MMM.
One last point to consider. With the rear mower off, I have full ground clearance when I really need to use the front end loader for digging into the soil or moving over or around sand or rock piles. That alone makes all the difference in the world.
Just my 2 cents...