Arai has been making helmets for a damn long time. They are both SNELL and DOT approved, and you can't buy a better helmet for your money. It all depends on what fits you best. Klim is a relative newcomer to the helmet and M/C clothing scene. Yeah, they are popular, but I don't think they are proven in helmet R&D. Arai is. Do your research on Arai. They have a helmet fitting process, and make helmets to fit all shapes of heads. I have the XD-4 and LOVE it. So comfortable. I have what is considered an "oval head." Look at Shoei, AGV, and Schuberth. A good helmet is going to cost you $500+. It's only your brain.