I've been wearing the JT Camo flex 8 full helmet since they came out (my father in law got it for me for Christmas that year). Great helmet, and I get shot in the back of the head often... Which is the price you pay if you are first into the other teams camp!
When my kids play I put them in it, and wear a regular flex 8. If you use a camera on your mask, the full helmet is WAY more stable than just a mask, as the helmet carries the weight of the camera much better, and you get more stable video.
Personally, I like the way it wears, as instead of being pushed onto your face like a regular mask, the top of your head carries it, and it just feels better than a mask to me... I have a fan on mine but I rarely use it. If you change your thermal lens every year you shouldn't have any fogging issues. Plus it goes down far enough to cover your chin and face, (lots of masks are so small, they leave the bottom of your face sticking out... OUCH!)