so the 4050 will work with .5 and above coils?? I don't go below .5 - it's my sweet spot.
It will work, but it's outside the rated output current for that regulator. From what I understand the 04050C can take quite a beating, but there's always a risk of component failure when running a part beyond its ratings. Also to run it that hard, you'll need a good low impedance battery (high drain) and a good battery connection with minimal resistance.
That quote is old, but I wanted to comment on impedance versus resistance. The difference can be subtle, but really only comes into play for AC loads. Since we work with DC and not AC, we can mostly consider impedance the same thing as resistance. Most simply, impedance is resistance with the added consideration for AC effects. What that guy said was sort of correct, but rather the AC part of impedance does not affect e-cigs. However the resistive part of impedance is still there just the same.