I know I said this before, but after buying and experiencing the EX800ST (taped), XB90Ex and ASG2.5 with the Cayin C5, I think I can say this with a little bit more authority, especially after getting the Moon Audio Black Dragon cable:
JH Audio Layla, with bass knob turned max, is basshead (not bassy) material, and should even rank in the top 10 list.
You may still be in doubt since it is BA, but coming from someone with the above IEMs, I think this statement goes a long way. Do go ahead and demo it. Not so sure about the custom version, but at least I feel this is true for the universal version. Given the sound quality, this may just be the best IEM for bassheads.
The Sonys although very good and clear in the mids, still have a slight veil due to the classic Japanese coloration. The Layla, on the other hand, is audiophile material, gets rid of the veil, yet still can deliver the bass like the big boys mentioned.
Don't get me wrong - I will still reach for C5 and Ex800ST for extreme bass stuff, and grab the ASG2.5 if I am on the go just with the iPhone and like some hard hitting electronics or hip hop that day, but if your song list is not purely made up of those (like mine), Layla may just be the way to go.
Cheers all,
Louis Armstrong