33 mah per flight sounds low, but I don't have alot to base it on and I don't know what you are flying.
I am averaging 80 to 90 mah per flight w/ 5 standard servos and a Voltwatch2 monitor running.
In either case with a 600 mah battery I wouldn't trust more than 3 flights without a good way to check the battery.
I am running 1500 mah pack in my plane so I can get a long day of flying in without much worries (plus, of course, I am using a battery monitor so I can fly closer to exhaustion without worries)