Fronts on the Sub's Amp

[Travis]

Big Daddy (and others),

What are the benefits and downsides of using a powered sub for bi-amping the front speakers?

If we do do it, which to send:
full-range signal amp(speaker out)to speakers(terminals) as well as amp (speaker out) to sub (input from amp)
or
high-pass signal amp(speaker out) to sub (input from amp) then amp (output to speakers) to speakers.

The above is from the diagrams in the manual for my ASW600 sub.

Note: If this was answered before, and I just couldn't find it, send me in the right direction and delete thread.

Thanks,
Travis