'thanks for the info... its all a big maze trying to define the differences and I guess it depends on how well one understands electronics which I am pretty sad when it comes to it.
I've got a couple of Raptor 120w boxes, because I was into strictly sub ohms for a year, and they max at 6v, but can have lots of watts.
Lately I've appreciated dna boxes because you can go with LR resistances (1 to 2 ohms) with thin wire coils, and crank up the voltage; the dna30 has up to 9v ! I use these with my favorite atomizers (single coil RTA's)
Now the Sig100 can also go up in volts (T8 etc too)... so imo those are pretty good for whatever you want to build; wide range in watts AND voltages.
I know there are things like "step down" and "boost" but I still don't know what the differences and strengths of how the double batts are configured ... I've been reading but even now its a puzzle.