Bijou owner here.

I cannot do any comparison to other model because this is my first audiophile level earphones.

First, the vocal of the singer can be hear clearly including the background music such as drum beats and etc etc.
My Bijou bass level is 3 too, and for me the bass is deep but still not enough for me. I prefer deeper bass maybe I should take the level 2 one.

Overall I still love this baby.

any good source to test the earphones ? recommend some.

Here is the review after 8 hours burn-in.

Shuang Jie Gun - The beats of drum are clear and the other instruments are played nicely. Seriously, this time I can hear what Jay Chou is singing, I mean I can hear the words and understand it. Normally, I don't know what is he singing and just enjoy the song.

Bei Pan by Gary Cao - The vocal of singer is crystal clear and I can feel the sadness in it.

The bass of the BiJou significantly become deeper and tight after burning-in. But, I notice some of the songs, the parts of the vocal become sharp.