I had over 100 hours in the standard seat in the MX6000 open station before I sold it and it was a much nicer ride than the standard seat in the BX25 that I had for five years. I have close to 100 hours in the MX6000 cab model with the air ride seat, and for sure it's an upgrade over the standard seat, but one was vinyl and this one is cloth so it's not really an apples to apples comparison. The cloth seat is softer and has more give to it.
I will say though, the ride in the M6060 with the standard cloth seat is WAY better than the ride in the MX6000 with the cloth air ride seat. I bought the air ride pedestal for the M6060 seat recently at dealer cost so it will be interesting to see if it makes the ride even more comfortable. My point is that the tractor model has a much bigger influence over ride comfort than the type of seat, and it's likely that the difference between cloth and vinyl might be greater than the difference between the seat suspension system. I only base that off a fair number of hours in a BX, two MXs and an M so admittedly the data set is small.