I believe the answer is in how well either alternative is implemented, like so many things in audio. I have tried it multiple ways and success was directly related to my skill level at the time.
From a speaker manufacturer standpoint, providing just 2 binding posts and preventing the inexperienced user from biamping insures the user won't mess up and their carefully deigned passive crossover will be used as intended. Then some speaker builders I think include two sets of binding posts because their marketing department tells them this is what customers want to see...I believe this is the case for B&W. I own their 804S speaker and like it a lot.
About 5 years ago I tried with my current speakers, my McIntosh MC275 for mids/treble, and a 200W SS for the woofers, both fed from the preamp. The MC275 have gain adjustment so I could level match both amps. Both amps were receibing the full bandwidth from the preamp. I didn't like it vs. only using the MC275 to feed the whole 804S.
A number of things I've learnt over these years and my system front end migrated to a highly optimized computer. Again, it's about how these are implemented. But part of the goal of using a computer was to allow me to use digital crossovers in there and have an active system, so a system where the DAC processes mids/treble, midbass, bass in a separate channel, feeds that to a dedicated amp, and the amp straight to a driver. So now the amp only receives the bandwidth it's supposed to play. I still have the 804S and the MC275 driving the midrange/treble (still using that passive xo until I get another amp), have class D amps driving the bottom of the 804S, and have powered subs. This is A LOT better than with the 275 driving all.
Performance now is much better than single amping. The regular argument then goes "but your amp section is now much more expensive". This is true, but when thinking the system as a whole I am doing without my beloved Lamm preamp, and using a more expensive DAC than I used to. All in all, my system now adds up to the same it used to - actually even less.
Still there is a hidden cost: I consciously gave up analog sources (even CD players from their analog outputs). By doing this I could focus on digital and optimize it. But my system has never sounded better. No going back for me. In fact, I'm moving forward yet: get another amp, and remove the passive crossover between tweeter and midrange.
Sorry for the long post!
From a speaker manufacturer standpoint, providing just 2 binding posts and preventing the inexperienced user from biamping insures the user won't mess up and their carefully deigned passive crossover will be used as intended. Then some speaker builders I think include two sets of binding posts because their marketing department tells them this is what customers want to see...I believe this is the case for B&W. I own their 804S speaker and like it a lot.
About 5 years ago I tried with my current speakers, my McIntosh MC275 for mids/treble, and a 200W SS for the woofers, both fed from the preamp. The MC275 have gain adjustment so I could level match both amps. Both amps were receibing the full bandwidth from the preamp. I didn't like it vs. only using the MC275 to feed the whole 804S.
A number of things I've learnt over these years and my system front end migrated to a highly optimized computer. Again, it's about how these are implemented. But part of the goal of using a computer was to allow me to use digital crossovers in there and have an active system, so a system where the DAC processes mids/treble, midbass, bass in a separate channel, feeds that to a dedicated amp, and the amp straight to a driver. So now the amp only receives the bandwidth it's supposed to play. I still have the 804S and the MC275 driving the midrange/treble (still using that passive xo until I get another amp), have class D amps driving the bottom of the 804S, and have powered subs. This is A LOT better than with the 275 driving all.
Performance now is much better than single amping. The regular argument then goes "but your amp section is now much more expensive". This is true, but when thinking the system as a whole I am doing without my beloved Lamm preamp, and using a more expensive DAC than I used to. All in all, my system now adds up to the same it used to - actually even less.
Still there is a hidden cost: I consciously gave up analog sources (even CD players from their analog outputs). By doing this I could focus on digital and optimize it. But my system has never sounded better. No going back for me. In fact, I'm moving forward yet: get another amp, and remove the passive crossover between tweeter and midrange.
Sorry for the long post!