I had an extra cat-less pipe that I wrapped with DEI's best wrap. The change in felt heat was amazing, I had it on for over a year and removed it and reinstalled the original and sold the wrapped one when I sold the bike. The guy who bought the header removed the wrap because he didn't like the goldish color, he only wanted a cat-less pipe, the pipe showed no accelerated rusting or change in appearance from when I had wrapped it earlier.
So I have to disagree with the wrapping makes for deteroriation of the pipe comments, sorry, but it did not happen on mine. Also I wash the bike weekly and never made any effort to prevent water on the pipe. I would start it and let pipe dry but otherwise nothing special.
I would do it again if my ankle was burning thru my boot like it did on that bike.