as A1 steak sauce said, there is a HUGE difference between trimming and debeaking. debeaking is horrible. i just can't imagine doing it, nor do i see the actual benefit. i know the industrial places swear by it (as do most ag extention people you will talk to) but i believe that if you have to mutilate a chicken to make your set-up work, you are doing something very wrong.
my brahma roo is getting his beak trimmed (well, rounded off really) this weekend. he's not aggressive, but if you pick him up he panics and bites-not pecks, latches on until he brings blood. that makes keeping a good eye on him really difficult. all the "experts" insisted i should have him debeaked, but i just won't. instead, we are using a drimmel tool (like you trim dog's toenails with) to just round the sharp point off the tip. no pain, no bleeding, no disruption of function, just safer hands for me.