My helmet weighs around 15 pounds and its not bad ! But my other ftp is around 12 or so , weight all on top not on the front without flash and it feels like im nakid without it on .If its balanced well ,it'll be comfy
Yes I have had several hard openings but it's not problem so far I can keep weight of helmet in my hands (handles in sides of the helmet are for that purpose, see http://www.kusti.net/images/kusti.jpg) during opening.
I have several cam mounting kits for my cam helmet, example with fs I use (obviously ;) one mini-DV setup.
My number of cam jumps is 993 with something around 1/3 of them with big setup on.