RE: Smart Fly?
Your servo choices will be fine. I have my first A123 battery and like it, but the only reason I have it is because it was given to me. I can tell you that they work great. The setup that I have is the one from Wild Hare, with the single switch with dual reciever leads. I have used Li-Ions the last few years and have been very happy with those also. Dual setups are a little easier with the Li-Ions because you can use the 2 cell batts and they are smaller than the A123's. Even with the regs, I think the weight is about the same as using one A123. I've used the Fromeco Sahara's and realy like those if you choose the Ions. The A123's are a little more user friendly with the quick charge ability, but they are not as easy to test for remaining capacity.