Without knowing why (neck & back????) you're being told no tractors, I too would agree that a bigger tractor is far more comfortable. My 75hp Mahindra is much more comfortable than my 32hp Mahindra. I would say that if you put liquid in your tires, you will find that your tractor will ride much much smoother. That is what I found on both of my Mahindra's anyway.
Good luck with whatever it is that you end up doing.
I should've mentioned that part of my problem with using a tractor is that I've pretty much lost the ability to turn my head enough to watch a cutter at work. Also, my local LS dealer got in a J2030H today and I rode around on it for a little while. I liked it, but it seems somewhat smaller than the JD 2720.I think Kilerbzz is on the right tract. You don't need another tractor, just better seating on the one you have. A $700 air suspension captain's chair would ease all your pains and be much less expensive, assuming that the tractor you now have is large enough to accommodate a big air-ride suspension seat. Go slower and reduce the air pressure in your tires and better seat might just be your ticket. I myself have bulging disc in my back, 3 surgeries on my neck to the point of only 3 vertebra actually move (titanium plate on two of them)and I still enjoy my tractors and lawn mowing. I do need a few Tylenol after a good work out though, but staying busy and moving around helps my severe arthritis also
Also, my local LS dealer got in a J2030H today and I rode around on it for a little while. I liked it, but it seems somewhat smaller than the JD 2720.