Although the C Plow looks slick, I doubt it really adds much to the PT plow with rubber strip. The key to back dragging away from doorways, etc. is visibility, and we PT types have that better than any other snow moving vehicle I've seen.. I have found that I can drop the blade within one inch of a doorway, and back drag as cleanly as if I were pushing. The rubber isn't at precisely the same angle, but does a good job.
Despite the claim on the website, I don't see the C Plow as a substitute for a loader. For moving deep snow or piles, the loader's the answer.
The rougher the area underneath, the more the need for blade trip. My area is pretty smooth, so I seldom pole vault with the rubber lip. I think I'd like the springs on Hans's reclaimed "cheap" plow, however.