I've actually been thinking about this for a while...note most of this is observation.
Microcoils have their place but lets look at it from a scientific standpoint for a moment, the issue is as follows being a solid cylindrical tube will almost zero air gaps dose not allow the vapor to exit, it gets superheated and then dispersed beyond functionality.
the only exit points are the entrance and exit of the tube leading to seemingly poor vapor production as it would stand, also the juice in the tube is not replaced therefore your technically only bringing the liquid to vaporization point at the two contact points of your first and last coil wrap.
Leaving a small gap (1/32'nd of an inch or so) would allow for the heating induction zones to be close enough for even heating, also at each contact point of the coil both left and right side allows for additional surface area for vaporization.
Ohms will only slightly fluxuate from micro coil to standard wrapping, electricity will follow the pathway of least resistance and that is the wire itself, I'd see it more important to get the wraps tight as possible to make use of the wire you do have which would give you additional surface area without wasting (NR-R-NR builds can shine here as your only heating at the point of the coil, no loss of electricity due to resistance from additional wire).
Sub-ohm vs Low Ohm vs Standard.. Well Sub ohm cooks the juice due to the high heat produced, Low ohm seems to work well at it will preserve the flavoring in the juice pretty well without any degradation to the flavor. I've not found any advantages from the next step up in truth.
.03 to .9 is sub ohm
1.0 to 1.8 is Low ohm
1.9 to 2.4 is standard
I'm a bit foggy on those so they may be a bit off, its been a while since I've had to think about it.
Higher Ohms, longer battery life...Lower Gauge wire (Size) the higher the amperage draw but the faster it heats up due to the lower resistance of the wire.
Just a thought, I have them from time to time.
