Currenty I own a 510 and want to go lower on my nic but find that the throat hit is diminished (huge factor for me). I would like to know the diff between the 510/901 battery strength vs the 3.6volt and 6.0 volt strengths, the size length of the 6v compared to the 3.6v, and how one can be 3.6 or 6v? Basically, I would like the biggest throat hit possible on the lowest nic on something that doesn't look/feel completely awkward when using it. Thanks for any input you can give me.