I've been using the LEATT neck brace for MX and Supermoto since they came out.
You really don't see too many MX racers/riders without one these days, because they work.
Lots of people ask about roadrace use, but the design was not ideal for use with leathers.
Leatt has changed this and has created a roadrace specific neck protection device.
I'll be sporting one this season, they're a good investment that will last a long time and survive many crashes.
More info below
http://blog.revzilla.com/2011/02/lea...ming-soon.html
http://www.revzilla.com/motorcycle/l...oad-neck-brace
http://www.shr.bz/new/L_110910_Leatt.pdf