I tried the Onkyo W800BT at ISSE yesterday, won my "most impressive gear" aware.
The bass is amazing and just right, the present is there but not overpowering. For a true wireless earphones, it's the first one that I tried that can play for extended period without losing connection between the left and right sides. Granted that this is played in a room with 10+ bluetooth connections in the air, that's fantastic to me.
Right earpiece can be used as a bluetooth earpiece, that's a bonus to me.
Only complaints that I have (and they are minor nitpicking complaints) are that the mids and highs are VERY SLIGHTLY recessed.
But given that these are true wireless IEMs that are source independent, this is a MUST-BUY for me.
Luckily my colleague is in Japan this week, so I quickly ask her to hoot one for me if she saw it there.