Keep in mind, I'm not saying they are bad, I'm simply saying A123's are better.

Li-Ion's require a regulator (another piece of equipment to possible fail), are still a fire hazard (although not half as bad as lipoly's), and only last about 200-300 cycles (if they are high quality).

I kind of chuckle when people say A123's burn up servos.....the MAX voltage of an A123 FRESH off the charge is 7.2, a 5 cell nimh pack - 7. People have used older servos designed for 4.8 and burned them up....some have even used older servos designed for a 5 cell nimh and burned them up, but I can tell you that I have used A123's with the factory recommended servos in a Bandit ARF (and there are some small ones in there) and I never had so much as a glitch. Use new equipment and you won't have a problem. Anyone that I have ever heard of losing a servo to an A123 was using a servo 4-7 years old. Within a minute of being turned on, they settle down to 6.6 volts where they remain for the majority of their ~2000 Mah life.

And yes, Li-ions have a hard time putting out the power required for some Kero start turbines, mostly the turbines using a 6 volt system (Jet Cat, Jet Centralm, etc,) The lower the voltage, the higher the amp draw.

Chad