Preferred radius on Mods?

[Zezak]

Just wondering what do you guys prefer the size of the radius on mods? Out of the Chi-you, nemesis and pux lux, I love the fact that most atomizer fit flush on my pux lux and nemesis.

 

[grindle]

I'd prefer 16mm but nothing below 22mm diameter and 100mm long seems to be powerful enough for dual-coils. Kind of forces my hand a bit.
And for some reason most drippers aren't 22mm. Can't figure that one out, it's slim pickings for the most popular mech size.