It's not what you get out of it, it's what you put into it. Record everything. And I do mean everything, even if there isn't a "fill in the blank" for it. Including weather conditions, ( temp, baro, and humidity, altitude, sun or shade on you and/or the target, etc), direction of fire (compass) and anything else you can think of. I'd also copy every page in it on to your pc before you enter anything in it, so when you need fresh pages you'll have them to put into a 3 ring binder later.