I initially had J&M BT03- the issue with BT03 is that with second headset connected I could listen to music, switch to intercom but I couldn't switch back to music. J&M sold them with upgrade once BT04 was available and they honored this commitment. The Fodsport behaves the same way as the BT03- riding solo it is non issue. The sound/performance is fine if using without intercom. Music, Siri and phone calls work well. If riding solo and you don't switch to intercom everything is fine.
I haven't tried the BT04 as they are on full helmets and they are too warm for me during nicer weather.
That said, if you ride solo, and don't care about intercom either the Fodsport or BT03 work well. Neither the Fodsport or BT03 worked correctly once intercom was initiated. I'd go with BT04 or a Sena set if you want to do it all (music, intercom, Siri) although I haven't tested BT04 yet.
I did have a problem with passenger mic making noise with Fodsport - I contacted seller on Amazon and he quickly sent out a new set of 2 headsets. There wasn't a lot of discussion about replacement. He was not aware of 2018 Gold Wing and resolving intercom/music. His solution was to pair phone to helmets rather than to the bike and check for issues. I didn't want to do that.