BikeBikeGoosewrote a review of Mavic Plasma Helmet on October 22, 2013
Familiarity: I returned this product before using it
So, the helmet looks pretty cool (though seems a little more mushroomy in person than it does in pictures). And I appreciate the reflective accents for riding near cars when it gets dark. But Mavic's size chart people were drunk when they did their measuring. The Medium is supposed to fit 54-59cm heads. I used a really accurate, soft/flexible metric sewing tape measure and measured my head SIX freaking times to be sure to get a perfect average to not have to deal with returns (and couldn't find the helmet locally to try in person). In no measurement was I ever above 56cm, so there was at least a 3cm margin of error. Well, when I got the helmet, I couldn't even get the helmet fully onto my head. It wasn't just tight, it wouldn't even go down all the way. And I have a pretty smooth shaved head with no weird bumps.
Anyway, the sizing fiasco gave me a chance to examine it more closely than my obsessive online research. While it's nice, it could use some more refinement. The Ergo Hold System seems a little flimsy and plasticy, and might get annoying on longer, sweaty rides. And the visor plugs/holes are REALLY tight. If you plan on swapping the visor on and off regularly, you should probably plan on the tabs breaking and needing replacements every few months. I sent the helmet back, and went with a Lazer Genesis. Much happier.
I'll give it 2 stars, just to be generous for some snazzy looks.
If you do order this helmet, though, be sure to add 3-4cm to your measurement.