I tested a lot of tractors from Kubota and NH this summer. And because I was buying something to mow around trees, work in ditches, and groom trails, turning radius was a key point with me. I did not look at SuperSteer, but I did look at the turning radius of several sizes of tractors from both Kubota and NH, as well as some 20 to 30hp Cub Cadets. All of them, for any given frame size, were comparable. A small frame NH turns in about the same space as a small frame Kubota or Cub. As frame size goes up from Class 1 to Class 2, the turning radius goes up. But all were pretty much the same. The dealer showed me a NH with SuperSteer that was on the lot and was bigger than I was interested in, it turned in a circle that is probably smaller than the radius a Class 1 tractor turns in!
Several threads indicate that SuperSteer is hard to get used to for people who do a lot of loader work, but some others swear buy it. I just know what I saw my dealer do with one and I was amazed.