U wicks do better at wicking than just plain vertical wicks. Done right on a good genny, you can chain vape a tank dry prior to getting a dry hit.
I like 325 mesh for 50:50 PG/VG I'm not real fond of the 400-500 range unless I'm using 100% PG juice. Playing around with different mesh sizes can yield good results.
Take your time and get a perfect glowing from the center coil prior to adding any juice. You'll find that seeing a hot spot is near impossible with juice on the wick, you'll taste it right away though.
You can run micro coils closed or open, if you have long legs on a closed coil and the legs are different lengths its going to be harder to sort out hot spots.
If you don't want to do the U wick thing use as little mesh as is possible, kind of like cotton "a little goes a long way"
You might try ribbon kanthal, I'm not sure I like it or hate it just yet.
Maurice