The new vertical coils are rated 15-60 watts, so if you have those you shouldn't be getting a burnt taste. I was getting a burnt taste around that same wattage with the .5 horizontal coils. If you're using the pre made coil heads, you can look on the side of them to see what they recommend you run it at. If you don't want a sub ohm tank, the Nautilus Mini is a great tank.
Right now I'm at 28 watts on my IPV 4s with the newer subtank mini with vertical coils and it's doing great. I'm using max VG juice as well. I know when I was using the horizontal, I had to stick a close-pin through the wick in the middle of the coil to get juice to flow, like Jim said, I had major wicking issues with those if I didn't. Not the vertical coils though. I can go up 40-45 watts without a dry or burnt hit.
I really think the Subtank Mini is a great tank, and I'm thinking it's the older heads that you have. I would check the side of them. If they say 15-30, they're the older horizontal ones. 15-60 is the vertical ones and if you're having an issue with those, you may have a bad batch.
Hope that helps.
