Massive overkill for the ignition. 1,000 mAh would have been plenty.

Something wrong with the guy only getting 5 flights on the 2,300 A123. Should be quite a bit more than that. I can, and generally do, more than that with a 1,000 mAh 4.8v nicad on a 50cc single. Using 70% as an A123 battery cut off point, or roughly 1,600 mAh, averaging 450 mAh/ignition hour, you should be getting close to 3 hours (lots of fudge factor) of ignition running time. Yes, I use them too and know that as the voltage drops the discharge rate increases. Are you running straight battery to the ignition? If so you're wasting a lot of flight time to heat discharged from excess voltage.

The flight battery is dependant on the servos and linkage installation. A 6v will run down faster than a 4.8 but you lose servo speed and torque. I would make it a point to field check that battery every couple of flights and recharge when the battery drops down to nominal capacity. Especially if you're using a JR 2.4 system, the "brownout" king.