Okidoki, I understand a bit better now. Thanks!Since the max voltage output is only 7V, you'll achieve 98W MAX on a 0.5ohm coil.
So lets say you have a 0.7 ohm coil... and you set the mod to 100W - it might read 100W, but you're only truly putting out 70W of power.
So to hit the 100W mark safely you'll need to build around a 0.4ohm coil or your reading will not be true.
The nice thing about the IPV3 is that it can step down. I'm not sure the Sigelei achieves this.
Step down being sort of what I just explained in reverse, if that makes sense.