What chargers are you using for your flight packs?
I'm using Lipo batteries and I use a celectra lipo charger. It takes about an hour or so to charge my 3 cell 1500 Mah pack.
How many flight packs do you use?
As many as you can afford.
What batteries are you using in your transmitter?
Duracell or Energizers AA.
When you fly when do you know when to stop flying?
I'll notice the battery doesn't have as much power as when I first start flying.
Do you stop before you start to loose power?
I quit and charge up as soon as the batteries goes down, the speed contoller in the CP doesn't have the correct cutoff for lipos.
When reaching the end of the battery charge does it slow down gradual or fall off fast?
On the stock Nickel metal battery the voltage drops off pretty fast and you'll notice it when the tail whips out of control on you. On the Lipo's it's pretty gradual, and then if it gets too low the tail will starts acting crazy too.