Coils choice all comes down to the surface area. Exotic coils like framed staple have the most. Twisted coils have a lot. Round wire has the least. Spaced coils have more surface area than contact coils. More surface area means more vapor, more flavor, and higher juice consumption.
Your next consideration is residue. If you use a simple juice like menthol, fruit or unflavored, this won't be an issue. If you use complex bakery flavors then you get buildup, and coils with nooks and crannies won't be the best choice.
When you use large coils that dissipate a lot of heat, exotics have an additional benefit: the surface area helps them cool down more rapidly because they are made up of many high gauge wires instead of a few low gauge wires, so they're less prone to scorching.
Then there's your choice of metal. I find Ni80 is superior to Kanthal for flavor and it seems to heat up more easily. I haven't tried any others yet.