Realwiz,
I haven't run the numbers on your proposed power set-up, but for my personal preference the weight difference between 12 CP1700s and 12 CP2400s really degraded the performance of my Magic. Still, I note that in an earlier post someone was using 3300s and was pleased.

As for duration, a wetpower flyer timed several of my flights and was getting 9-10 minutes. He was so impressed he askd me to set-up 3 Magics for himself and two firends! He's loving it(-:

I set my timer for eight minutes and always have power to land.

I also found out that by feeding a little down elevator while taxiing the Magic ground handles quite well on grass.

I've just upgraded my Schultze for LiPos and will be going to the trade show in Rosemont, Il. this Saturday. Hoping maybe somebody will have a show special. If I've got it figured right I'll need a 4S4P pack to equal the performance of my NiCds. (12 1700s pulliong 35 amps in hover).
Walt