I haven't gotten to watch Dragon Ball Kai yet, though I'm hoping to-- Dragon Ball Z without the filler and time stretching? Talk about an idea I can actually get into!
Unfortunately, Sankaku Complex reports that the series is being heavily censored for violence on Japanese TV...which seems to speak to a growing conservatism in Japan. At least, assuming that the comparisons are being made from the original TV broadcast version versus the new one, as opposed to the VHS/DVD release compared to the new one.
That said, you can definitely se a significant difference here-- the art may look nicer, but way, way less blood. Which makes me a lot less excited for the possibilities of the show! How about you?