i found links like: http://www.audioholics.com/education/fre...ing-vs-biwiringhttp://www.chuckhawks.com/bi-wire_bi-amp.htmhttp://www.ecoustics.com/electronics/forum/home-audio/160189.html
as i read it:
There are no any negative answer about bi amping.
Bi wiring one amp with Speacker A+B output instead on each speackers Is silly.
Vertical amping is to try before doing more advance tweack with active amp+ external crossover that breack warranty most of the time.
Forums users who tryed it may notice some change in both case.
bi wiring 4 mono blocs is really different from what i tryed with my hk675 integrated stereo amp:
with other speackers capable of bi amping ; it's a silly thing i did on my own to cut speacker cables in four equal lenght for no improvment.
If i was using 4 monoblocs like you or either two amps it could be ok but definitively it's a no no to waste cable on bi wiring if not used on a passive/ bi amp setup.
One monobloc per speackers:
I will maybe make a move for that solution even if it require a preamp compared to an integrated amp.
For my usage it should be ok.