http://radhikageorge.files.wordpress.com/2009/03/can_of_worms.jpg TBH mate you are asking lot's of questions with lots of answers... Stick to the basics Does it fit properly... I mean properly. No loose points, and no overly tight points. Is it appropriately approved for legal use in this country. A £40 helmet that fits perfectly will be safer in an accident than a £400 helmet that does not fit properly. I wear a Shoei. Not because I like the helmets they make, or the brand, or that they are popular, but because it fits me so perfectly it's like Shoei use my actual head as a template!!!!!