The only difference seems to be if you go to the Blackberry Extras website (http://mobile.blackberry.com)
. The Cingular Browser renders the B&W version of the site while the BlackBerry browser renders the flash/animated color version of the site. But this appears to be a function of the site and not the browser since my desktop IE browser also renders the B&W version of the site as well. But since this is a very cool site that I use as my home page, for that reason alone I would use the BlackBerry browser. But unfortunately, since I don't have BES, I am stuck with the Cingular Browser.