Great thread.
I keep my Magma around 0.5-0.6 ohms with 26 gauge, 0.8 with 28 gauge, or 1.4 ohms with 30 gauge. I've settled in with using the 26 gauge, even though the 30 gauge is probably the best vape.
Here's why: 9 wraps of 26 gauge is a lot easier to manage than 12-13 wraps of 30 gauge - simpler build (and 30 gauge has a tendency to break in the post holes). Also, the thicker wire gunks less and lasts longer than thinner gauge - less rebuilds. Third is wicking - the center of the coil heats faster than the outside, and is harder to keep saturated.
Sure, ohms don't matter too much when it comes to the actual vape (the 30 gauge is awesome), but my 26 gauge builds are more convenient.