Passive vertical bi-amping with 440 Pro

[Soniclife]

In my opinion it works well, the difference is quite subtle, but I notice a little more precision in the placement of performers in the sound stage, and in the timbre of instruments, which I was not expecting.

Have you noticed any change in headroom or volume settings.  I run my 440 close to 0 vol sometimes and would be interested if I would gain or lose going to bi amp mode, however it it simply sounds better that would win.