I have both, but I’ve only used the GonG so far, those have been out for years so that’s what I stocked up on. They recently came out with the SonG and I picked up a couple during the BOGO sale a few weeks ago, might come in handy for travel. They ran sales for 4/20 and in May, so I’m sure they sold a lot and they’ll be restocking those 14mm GonG stems soon.Okay, I will take a look at the Epic WPAs. Looks like the 14mm GonG is out of stock right now...guess I'll have to wait. Which do you prefer, the SonG or GonG? I've never used silicone pieces.