I'm not sure it affects choices so much as dynamic range.
Since bass signals soak up most of the voltage swing, eliminating that from the amp's output means all of the voltage/power swing is available for the mid and treble. Also, the amp acts more "stiffly" than otherwise. Like you mention the high current requirements are reduced, so the power supply sags less.
In general, no, you don't need massive amps for the top part of a bi-amped system. As for the rest of the quality, I don't know. :) I mean I really like the sound of Ayre, but bi-amped, Parasound A23's may work just as well.
Best,
Erik
Since bass signals soak up most of the voltage swing, eliminating that from the amp's output means all of the voltage/power swing is available for the mid and treble. Also, the amp acts more "stiffly" than otherwise. Like you mention the high current requirements are reduced, so the power supply sags less.
In general, no, you don't need massive amps for the top part of a bi-amped system. As for the rest of the quality, I don't know. :) I mean I really like the sound of Ayre, but bi-amped, Parasound A23's may work just as well.
Best,
Erik