If you mean parallel vs serial
Parallel Pros:
much less of a pain to build
Heats faster
Easier to wick
Cons:
Requires more voltage
Basically reverse those for serial
Now if you’re talking dual vs. single coil
Dual pros: more vapor. This assumes similar sized
coils. Single
coils are often built in larger diameters.
Cons:
Coils must be perfectly balanced for good TC
More
juice used
More electricity used means shorter battery life
Ohms cut in half means high voltages