I would add, if you go lipo and want quick response, get an ASCU or similar control unit. Will cost between 75 to 120$ approximately, and will provide not only a way to monitor and prevent damage to the battery, but also provide a much quicker trigger response.
They basically replace the trigger contacts with a microswitch; Day in night if you ask me. Some also have active breaking, 3 round burst mode, etc etc
Originally Posted by Brian McIlmoyle
Real life comparison,
GBBR- bang bang -- Giggle
AEG-- merrrzip merrzip -- meh