I have a Shoei fx-4 and I did wear a Bell moto-6. Both are very good helmets. For the best protection I would go with the Arai or Shoei VFX but at the cost it is hard to swing especially considering helmets are really only good for 1 hard hit. I mean one that gave someone a concussion. If someone gets hit hard enough and you get a concussion, black out or get very dizzy that helmet is trash. The foam in MX helmets do not return to their original shape after a hard hit.
Most helmets that retail around $200.00 are good helmets. They probably do not fit as well or look as pretty as the ultra high end ones though. Look at the Thor, Oneil, Bieffe, MSR that fall in that price range. It is your head and needs to be protected properly.
Matt