I have the 60" MMM on my
B3030. I thought about getting the 72" but did not because of concerns regarding the drive over mounting. According to the manual there is quite a bit of prep needed before you can drive over it. I have since read that it can also be rolled out from under the tractor, also. I also stayed with the 60" because of my leaf vacuum from my previous tractor which had a 50" mower. I don't think it would work on a 72". I find the 60" very simple to R&R. Just turn the left side anti-scalp wheel 90 degrees and roll it out on the right side. as far as scalping, it has not been a problem with 60" and I have a few eneven places around the yard where scalping can be a problem. One thing that the 60" does that I did not like is leave tracks in the cut lawn from the two center rear wheels that it rides on. I modified mine so the rear of the mower hangs from chains from the frame. I like it a lot better that way. I removed the rear wheels completely and now it it is even easier to R&R. If I had a large relatively flat lawn to mow I would have the 72", though. With the 60" it takes just over an hour to mow 1.5 acres with trees and landscape beds. It really eats the grass and I usually mow at full HST pedal in Medium range.