Someone mentioned that the manual talks about the infamous "Stax fart" as normal and nothing to worry about. Do a search on that. In short, the phone makes weird noises (sounds like electrical short) when you keep mucking up with the earcups. I haven't been able to confirm that the manual actually mentions this since like those of most folks here, my manual is in Japanese too.
I am not aware of any other things to consider except stock up on music.
Looking forward to your impressions on the KGBH/O2 combo.
<edit> oops, just read your sig, and see you have a kg bh - congrats!</edit>.
I have Omega II with a Stax 007t, and have English manuals for both. Reading through the manuals, there is nothing to really be concerned about, but if I can answer any questions, will be happy to do so.
Regarding the famous Stax fart, the O2 manual has an insert which reads:
The SR-007 is a precision instrument. Please handle with care.
Because the earpad of the SR-007 is completely airtight the diaphragm is most susceptible to the air pressure difference between internal and external barometric conditions.
These conditions can lead to minor noises emitting from the earspeaker when positioning on the head.
This noise will in no way damage the earspeaker or in no way effect the performance
I was listening for three hours now and the first thing I was worry about, was a low buzz coming from the KGBH. First I'd tried to reconnect the jack to the socket and this helped but not for long since the buzz later on started again. When give a little pressure on the back of the unit then it stops. Maybe a bad connection. My seller told me there is an "always ON bias supply" in this KGBH unit. Possibly it has something to do with that?