Hello Fractal,
first of all thanks for the answer.
As for the photo-realism in general, I think everything depends on the background.
Surely, with a background would have given a whole other level of photorealistic rendering as a whole, but as I wrote in the Making of, I deliberately sought this final surrender. Enhancing more the object with a composition of the study. If I put on a table with papers and films, you would lose that sense of importance that I give. This is the thought that I did when I made the setup for the steel. My2Cent
If the problem is given by some material or light, I would be happy if you could tell me where is the mistake in order to correct and improve. It is said that my method or idea is correct, then I'm open to any advice that I also help to analyze my work with more objectivity.

i7 970 3.3 GHz | 12Gb Ram | GTx550Ti for display + Gainward GTX580 1.5 Gb and Zotac 590 3 Gb for Octane | Win7 x64 __ Softimage 2011.5