I have an audio CD of an excellent presentation on cleaning and sanitation that Jef Stebben did at the 2008 Winemaker Magazine conference. If you listen to his talk (and some of this is in his slides, see below) you learn that B-Bright (or things like it) is not technically a sanitizer AND that K-meta at room temperature is not a great sanitizer (it IS at 148 degrees for 20min). That said, it seems clear to me that both B-Bright and K-meta are "good enough" at sanitizing for many home wine making purposes.
Being a rather obsessive person, I clean with One Step and sanitize with IO Star Iodine Sanitizer. Neither require rinsing, and IO Star will sanitize in 1 minute at room temperature. It is also easier on the lungs than K-meta. Iodine will stain plastics, but I have not found that to be a problem.
Jef's slides are at his website which is stebbenwine. com. It is on the Links page.