Thanks for posting. BTW, the link that you posted has been flagged for removal by Craigslist. I couldn't gain access.
Road graders benefit from have a very large spacing between the axles to damper unevenness soils/gravel. It is similar to the difference in ride between an extended cab pickup and a jeep wrangler. That tractor wheelbase will prove pretty difficult to get fine grading results. Looks cool though!
Dagoof said:You're right. A tractor will never be as smooth as a long road grader, but it will still be smother than anything mounted on the front or back.
Front or rear implements dig in or rise up when your tractor goes up or down and angle. Mid mounted blades always take the average of the front and back axles, so it tends to even things out more. Also, I'm thinking that you'd be able to maintain better down-force with a blade mounted in the middle.