Well, I found an even better combo now, lol. Got fresh 3V batteries and a 3 ohm atty from Avid Vaper and am using it now with 6V. Closest feeling so far compared to 5V with a standard atty. Best combo yet! (Although with all the different things I am trying, who knows?)
I've got a pair of non-rechargable CR123's I bought in desperation a while back, been thinking of trying 6V at least until they're dead. Highest res atty I've got is 2.4 ohm, so it might be a bit over the top....