When I was still new to RDA's drippers I always used to get the metallic taste until I learned a lot more about it.So I recently purchased an IGO-L and have been experiencing some very bad taste and smell. Getting the ohms just right hasn't been an issue for me and it seems like the coils I make are pretty good from what I have to compare them to online. At first I thought maybe it was how I wicked the coil (using cotton) but I tried so many different ways from making the cotton tight against the coil to making it very lose and everything in between. One thing I've noticed is that when I heat the coil on my mod to pinch the coils together there is smoke coming off the coil and it smells terrible.
I'm currently running a 1.6ohm micro coil using 28AWG on my MVP and even at 3.3V I still get that bad taste/smell. I must be missing something. The Kanthal is from Lightning Vapes if that makes any difference.
Every Atomizer you get your supposed to clean it before using it because of the machine oil they use to make the product.
What I do is I use toothbrush and some dish wash soap to clean my attys from machine oil since dish wash soap is a degreaser it really helps to get all that machine oil out. Remember to remove the o rings as they can swell up