Jeffreybehr...It ain't rocket science. I've been doing it since the 1950's. But it is less beneficial today since power amps (except some tube units) don't sport one percent or more of IM distortion, and watts are cheap. Passive crossover components are also markedly improved. It is, however, almost essential for subwoofer crossover frequencies.
Of course the internal passive crossover ought to be removed, except leaving any networks dealing with driver anomalies. However, I believe that even if you leave the passive network in place, which is what people are doing when they "Biamp" without an electronic crossover, (which I like to call "dual-amp") there is still advantage to inserting an electronic crossover. The woofer inductor will not be vulnerable to saturation distortion, and the tweeter will be protected from power amp "thumps". Also, the power amps will not have to carry signal that will be filtered out later, so headroom is improved.
