Now there's something I've wanted to ask about.

Those A123 batteries, can someone who's used them for a while give me a comparison to Lipo's.

Run times, punch, etc.

well.. you can pick up 10 for $110 shipped...
only disadvantage is that they seem to drop voltage pretty quick... other than that, they are beautiful...

I see. Dropping voltage at a rapid pace wouldn't be too good on the track. I'll stick to lipo's for now.