[RC-Monster Mike]

2 16x4 vs 1 triple pro - either way will work fine. The dual 16x4 will allow you to charge up to 30 cells at once(you could charge a 9 cell pack and a 6 cell pack at the same time)! The 16x4 is also smaller (both 16x4 chargers are about the same size or smaller than one triple pro). The triple pro is out of stock right now, too. the mv setting determines when the pack peaks (how the charger knows the pack has peaked). In general, a lower value will work for matched cells (3mv for example). As the packs get older or become unmatched, or when using unmatched packs, the value should be set higher (9mv for example). The actual setting determine the amount of voltage drop required to tell the charger that the cells have "peaked". when your packs have peaked, they will probably read somewhere between 12 or 13 volts.