Summitwrote a review of POC Cortex DH Helmet on July 19, 2012
The helmet fits well. It's #1 focus is safety. I do not want a TBI, even a mild concussion, again. I chose POC as my best bet, particularly for their dual layer system (decreases maximum force) and their MIPS system (decreases rotational forces that cause concussions).
The M/L fit is similar to my Giro Remedy CF medium. I liked the Giro, but it was old and I chose to upgrade. Compared to the Giro, the construction is better, the protective features are better, the hearing is better, and I am thinking the visor won't randomly fall off like the Giro.
The Giro is notably cooler when standing still, but the Cortex DH's venting system works very well when moving and isn't notably hotter than the Giro.
I use this for DH Mtb and skiing.