I now run the Troy Lee Designs SE3 and the GPX. Not a cheap set up but it works really well. I've had a lot of head hits and a lot of concussions in bicycle helmets. I'm a big fan of the moto, but the D3 is a sick option as well, only bike helmet I would consider wearing now.
I have since yesterday a Arai VX-3 Pro to match up with my Leatt GPX,more likely the most expensive setup of them all.In my opinion the Arai helmet is the best compatable helmet for my Leatt brace.Tons of head movement even in the attack possition i still head room left.