Might want to look at the steeljan video on the twist. Somebody wrote down the numbers yesterday (i'll look), and there was a comparison of the 1.5DC and 2.5SC and the max wattage was about the same, so i'd imagine the least strained (amps) to get to that number the better for the battery and carto/atty.
I'd think that to test your juices from cool to hot, a good way to do that would be to have the ohms in the middle-2.5,3.0.
Load 2.6 ohm Boge Carto
Setting/ Avg Volts/ Current/ Watts
3.2 volts/ 3.22/ 1.32 amps/ 4.2
3.7 volts/ 3.55/ 1.46 amps/ 5.2
4.0 volts/ 3.87/ 1.60 amps/ 6.2
4.4 volts/ 4.22/ 1.75 amps/ 7.4
4.8 volts/ 4.85/ 2.04 amps/ 9.9
Load 1.2 to 1.5 ohm DC Carto
Setting/ Avg Volts/ Current/ Watts
3.2 volts/ 3.19/ 2.47 amps/ 7.9
3.4 volts/ 3.49/ 2.68 amps/ 9.3
3.7 volts/ 3.48/ 2.69 amps/ 9.3
4.0 volts/ 3.46/ 2.65 amps/ 9.2
4.2 volts/ 3.46/ 2.66 amps/ 9.3
4.6 volts/ 3.43/ 2.65 amps/ 9.1
4.8 volts/ 3.43/ 2.65 amps/ 9.1
this
thread, page 77:
http://www.e-cigarette-forum.com/forum/joye-510/65055-battery-voltages-surprise-77.html