Finally receive my 4Ai,
when i start listening to it, WOW is the first impression i got.
The clarity and accuracy of the earphone, is something that i had never listen to before.
You can listen to every little detail of the song, and instrument separation is very good too.
Compare to the 3Ai,
the 3Ai have a more up front presentation, and more bass quantity and bass extension.
Happy for you that you have just got on board! They really are WOW aren't they! Maybe you understand why i love them so much now ;)