Penn stythe, your statement that "the biwire bypasses the crossover" makes me think that you mean biamping, not biwiring. With biwiring the full-range signal coming in via the wire feeding the tweeter has to go through the high-pass filter section of the speaker's crossover network or the bass will reach and guickly burn out the tweeter; similarly the treble component full-range signal coming via the woofer wire has to be removed by the crossover's low-pass filter or it will be fed to the woofer and be wasted because of the mass of the woofer cone. In biamping the full-range signal is split by an external (and expensive) crossover network BEFORE being fed to the power amplifiers, of which there must be TWO for each channel if the speaker system is two-way, hence four power amps for stereo. (For five- or seven-channel HT, do the math and shudder.) The advantage is that the power amps' output goes directly to the speakers rather than to any internal crossover network the speaker may have - assuming it can be bypassed. But this theoretically superior method absolutely requires at least four power amplifiers. If there are only two, we are talking about biwiring, not biamping, and we're NOT bypassing the speaker crossover.
Of course a powered subwoofer system is essentially biamped if it's running in stereo, since either the sub's crossover or a unit like the 990 does split the full-range signal into two parts (the low bass and everything else) and sends the former to the subwoofer amp and the latter to the power amps (or power amp section if it's a receiver) to feed the main speakers, crossovers and all, plus whatever center and/or surround channels there are.
Clear, I hope?
BTW I would say, "as always in audio, if it sounds good...consider adding it to your list of financial desires and priorities. Where on the list is a matter outside the range of this discussion."