I had purchased an fxa2 from Amazon and had the same issue. The sound would cut in and out just from moving my head slightly, even just chewing gum sometime. I'm pretty confident it was an issue with the connection between the cable and the earbud. While firmly pressing in the cable and rotating it helped, i was also surprised that the issue actually improved over time with use. However, after trying to reach out to Fender with no good response I ended up returning it.
In regards to the sound quality, I found that it had both big strengths and weaknesses. It had a sound that I would describe as very dynamic. It made it sound amazing (particularly relative to price and components) for very select songs, but ultimately I listen to a wide range of genres and it just wasn't well rounded enough for me.
In regards to come, and trying not to get into too much detail, the overall frequency response was not very smoothly tied together, which may partly be a limitation of only two drivers, and partly due to the fit. I had a really hard time getting these to sit properly, and they were fairly heavy and bulky (relatively), but can be comfortable when you finally get them in the right spot. The sound was noticeably better when I would press on the earbuds while listening, and it may just be they just didn't work for my particular ears, but even when they seemed to be fitting really good, there was the same issue. Also of note, it was very sensitive to eq'ing, which again may be due to the amount of drivers.
I ended up replacing it with a Promo 8 I got from massdrop for about the same cost and have zero regrets. However, there hints of greatness, and I would be very intrigued to try one of their higher end models. I would just strongly recommend trying before you buy if possible.
