I agree with some... disagree with some... Dune riding on 4-strokes is great! You don't need the high-revving power to get going like you do on a 2-smoke. The power is there instantly and smoothly, therefore it doesnt take forever to get going. As far as being dangerous, a good point was made earlier that I agree with. Mud riding can be much more demanding on an engine and bike. In the dunes, as long as you keep your airfilter cleaned, I'd say you are good to go. It does put a little more strain on your engine, but I dont think your engine notices it. Just let her cool down every now and then and I'd say you'll be good to go.