After rebuilding coil heads for my wife today I had a though. She complains that the rebuilt coil heads have an odd taste compared to the ready-built bubble packed ones she orders. When I was still using the evod I had the same problem. I use an Igo-W rda with the same wick I rebuild her coil heads with and have not noticed any bad flavor. So here's my theory, handling the wick as much as it takes to rebuild a head compared to recoiling an rda can and will rub off body oils causing a foul flavor. If anyone has any theory's on how to test this, I'm all ears.