When I was looking at mowers for my 230, I looked at both types. The MMM was only available in 66". The price tag on it was $3200 or somewhere around there, I don't remember exactly. I ended up with a 72" 3 point that I bought used for $400. It mows great! I was told by my dealer that I could use up to 84" and I may upgrade at some point.
One thing to keep in mind is the weight of the tractor. The wheels mash the grass down so that by the time the mower gets to it, it is still mashed down a little. I don't know if the MMM would be better in that regard or not.
I have the GP tires and live in IN. I don't know what kind of grass you have, mine is more of a fescue. I mow around 4 acres and have lots of trees but I also I have a ZTR to take care of all the trimming.
Hope that helps.