My first battery was (and still is) a large 8.4V 3300mah. I ordered this battery and a stock TM AEG 3 years ago with no "real" knowledge (only internet research).
I didn't think much of trigger lag much till I fired Styrak's P90. The lag was very noticeable. I guess I just started out right but never knew it
Oh yeah and I charge my battery like twice a season.
Large batteries or die!