Hook,
I have been using 1300 mAh 4 & 5 cell Ni-Mh packs with an Oddino regulator in several airplanes now, with digital servos. Zero brownouts, I can get about 8 -9 flights with a saftey margin. I check my packs with one of those ESV's with a 1/2 amp load. this is on my Focus Sport. The smaller Classic models seem to draw less current (lighter/smaller control surfaces), and I don't yet know the upper limit of flight time on those yet.
I recommend checking your packs with an ESV with a load, then you will always be sure before you push the throttle forward. Log the number of flights, and check the voltage each time. Then you will have solid data with which you can establish performance parameters regarding flight time for a given set-up.

I have yet to experience a brown out (thank God).