Keep in mind that loading the rear tires of an MX6000 adds about 1176lbs of weight, or the difference between the M6060 vs MX6000.
I seriously considered the M7060 or M6060 tractor compared to the MX6000, but ultimately chose the MX because I wanted an HST transmission. The MX6000 is the maximum tractor you can get from Kubota with a hydrostatic transmission. Frankly, the M60 series is far "more" tractor...for one thing, you are getting the 3.3L I4 instead of the 2.4L I4 in the MX. Even though the horsepower is similar, the MX engine is cranked all the way up while the M60 is understressed. The M60 also has considerably larger tires and a couple of additional features on the instrument cluster more similar to the Grand L. That said, I do slope flail mowing and wanted the very precise and effortless control of the HST while on steep slopes and near water. And so far, I'm happy. The A/C condenser screen is poor quality and needs to be cleaned frequently, and the cab could use a bit more insulation, but the three range transmission is working fine for me. I miss the Grand L's digital cruise control probably the most, followed by the very informative message center.