Incidentally, locally several friends wear Smith helmets with Koroyd crush zone liners, or Bontrager WaveCel. They're mostly casual cyclists and seem happy with them. I considered it but I often ride in midday summer heat and can work up a good head of steam even in cool weather, and most folks acknowledge those helmets aren't quite as well ventilated.
The POC Omne Air Spin is the best ventilated helmet I've worn, scooping air across the head. Friends with the Octal and Ventral helmets say the same. While I've been generally satisfied with Bell before I probably won't get another unless they redesign the harness. The main thing I like about the POC is the comfortable and secure harness. Bell harnesses in both medium and large don't quite reach the hollow between the base of my skull and neck, so they never feel quite secure -- although I haven't had one pop off my noggin in a fall.
However the Omne is more of a commuter or casual cycling helmet, but much better ventilated than the typical Bern or Nutcase. When I'm in the drops or on aero bars the helmet protrudes into my peripheral vision just above my brow. I'll probably get an Octal or Ventral for next summer. They look goofy no matter the color or model, but they seem to do the job. The thicker EPS foam seems like it should hold up well.
The worst crash I've personally witnessed occurred last summer when a fellow in front of me nicked a seam in the pavement that went from flush to about an inch higher on one side. I kinda cringed when I saw him riding that seam and, sure enough, he nicked that uneven bit, lost balance and fell hard sideways. I've since heard stories about other cyclists falling on that same section of road because the unevenness of that seam is difficult to see -- good reason to avoid seams or asphalt repair patches completely.
His head smacked the pavement hard on the side, then he slid about 10 feet headfirst into a curb, striking the top of his head. The helmet was toast but he didn't have an open head injury, although he was in shock and quickly showed signs of concussion. He was still coherent for a few seconds, then began repeating the same panicky phrases. Fortunately paramedics or EMTs were accompanying us on that ride and attended to him within a minute.