I had a Super-O layout in the Seventies, and loved the stuff. Why Lionel didn't continue with it in larger diameters, I have no idea. I have no problems with FasTrack, but Super-O looked much better.
As for the old "cutting the rollers" refrain, I can only say this: The only roller grooving I've ever had is on the tender of my 1951 2026. And that locomotive has never run on anything but 027 track.