Usually do lung hits with the zenith i run it probably half open on single coil....i find that while it does make a little more vapor full open the loss in flavor is pretty dramatic. Sometimes i find myself doing mouth-lung hits on it and it works pretty well. I dont have any problems with how fast it heats up (almost instantly) but i am usually about 7.5 volts. I tried 2.7 ohms (28g 16-18 wraps on 5/64) and thought it was a little slow so to heat up so went back to the 30g wire. What RDA are you using? Any suggestions for a Russian 91? I usually run it about 1.6 ohms 16 watts.
I've got some Igo-W's and a Taifun Gt with The Dripper attachment. I'll probably do it on the Taifun because there is more room. I don't have a kick for my mechanicals, so 15 watts is the max with the Provari. I don't know anything about the Russian, but 15-20 watts is definitely my sweet spot unless running dual coils.
As I understand it, everyone went sub to get more heat and watts on mechanicals, but if I can get the same heat and watts with a VV it should put out more vapor because of more surface area. Same kind of theory as dual coils, but I find dual coils aren't all that special with my slow inhales, I think it's the two airholes. I've got some duals on some Igo-W4s right now, but it's just more of a hassle to rewick for a vape that is not any better for me than single coils.
So yeah, didn't get around to it tonight and I'm going to bed, but it has been a thought lingering in my head for a few days now. I'm gonna make the coils 1mm spaced, as I think some vapor is pulled off the wick, so it will heat up slower than a tight coil. I'll let you know how it goes when I do it.