your looking at it a bit to simply, a good complex coil holds liquid within inside itself that creates more surface area and vapourisation. You can use less power with them if you keep the mass down. Dripping on a good complex coil is nice as the liquid just gets sucked in instantly saturating the coil and cotton inside it.
A well made coil will last many months, it's my hobby that i really enjoy so I just try to get best out of it as I can, with some of juices I'm using nowadays.
The only time I wind a roundwire is for MTL rtas like the picatini, though most times for MTL I use 30x2/40 fused Claptons as I'm a bit closer draw with a bit more power.
Not trying to be argumentative it's just my personal experience so far.