I angled my down and found very little difference. I ended up having super quiet pipes made up by Breeze Automotive but I still like the look better of the down turned tips. I've never noticed them blowing enough dust around to the extent that it bothered me but then again, I'm not standing still when I rev the engine. Works great for cleaning the freshly cut grass from the drive. I still have the other set of VERY loud pipes angled the same way that I can throw on when I need my noise fix now and again but I'll still take the quiet pipes over the loud any day.
