Here is my review of the Klim F4 helmet.
First its a very snug fit. The cheek pads loosened up after 2 rides and the helmet is much more comfortable now.
2nd there isnt much room between the nose piece and the goggles and i have a really hard time reaching in and pulling the balaclava up over my nose
3rd after 2 days of riding in waist deep snow, heavy snow fall, and carving some sick powder lines, i noticed two things. 1 - the vents never clogged with snow (like some say they would and 2 - without the gortex liner, my head got really cold (which is going to be awesome in the summer)
One could make the arguement that the snow is different here in Utah than washington, canada, etc. but shouldnt the lighter drier snow pass through the vents easier and fill up my cranium bucket with snow, melting on my head and getting me wet? Rain is a different story, and i would fully expect any helmet placed under a water hose to get soaked...
4th is goggles that fit: Oaklys didnt fit so great, my Spy Targa 2s fit perfect and the Scott high voltage 3's make a really comfortable fit as well.
Last is protection. On my first ride with this helmet i had an encounter with a tree. I hit hard enough to spider crack most of the back of the helmet and destroy all the vents. I think the helmet did an awesome job of protecting my head.