Here is a good read that will help answer questions about sanatizers. The LD Carlson site is very vague but the description and packaging leads me to believe that it's just another sodium percorbonate type solution, ala OxiClean, Powdered Brewery Wash, and Straight-A. The packaging says its a "No Rinse Cleanser" and says nothing about sanatizing.
Another big difference is contact time when sanatizing with StarSan or Iodophor compared to One Step or other such no rinse products. I think the biggest thing about StarSan and Iodophor is that they require very little contact time and can be reused numerous times. Not to mention that a little bit goes a long way.
I suppose in the end it all comes down to personal preference but I think you will see that many people around here prefer to go with the two step method, cleanser and then sanatizer.
But hey, I'm no Northern Brewer and my experience with LD Carlson products is very limited