i had one solidly affixed to the coil, took a fair amount of heating and twisting to get it all out.
I'm using my "tankomizers" aka Sapphire Bud, on a Leo which is 3.7. I have had a leaker, and did get a nasty burnt taste. There is a problem with wicks, and as I posted somewhere, it appears some of the tankomizers have the wick intertwined with the coil. Once they start burning, you really have to burn it off, as it ends up darkening the juice, giving it a nasty taste. Once I put in a new wick, did a burn off of the old wick in the coil, gave it a vinegar bath, yummy, yummy, yummy. My daughter's has been perfect right out of the box (I never liked that child!) and she's using a Leo also. Once the wicking problem is corrected, the only other thing I'd like to see changed would be a larger tank, especially for when I'm on the road going to appointments! Are they going to sell the little tips for the tankomizers separately, for those of us that may lose tiny things?