There's a story that they put a form of PG on the metal mesh as the strips are coming off the line before being intertwined - like how a cooling liquid is used on samurai swords coming off the heat. Whatever they use now, it's not nearly as nasty as it used to be. I still have the bad stuff on some early bulk buys. I think they used a dekang pineapple PG and if the story above is true then it likely picked up a metalic taste as well.
The primer on the mega eGo attys is pink stuff and doesn't taste that bad but I still blow it out, but don't have to soak it in vodka like the older 510's.