use supplied crossovers or not?

I have an older Alpine HU (CDA-7897) that I have been told is a really nice piece (hope it hangs on a little longer)... it has an active crossover setup in it to adjust freq. points and such.  I originally was running Boston Z6 components and was not using the Boston crossover that came with it.  Instead, I was selecting appropriate freq. cutoffs from the deck and was powering the 2 mids and 2 tweets with a JL 300/4, so 70-watts to each of the 4 drivers).  So the crossovers sat in the closet until I recently sold the components.  I just ordered some Pioneer Premier components and was planning on doing the same thing.... just wondering is this is really the right way to go?  I have been told by "audio people" that by running the drivers active, more of the amps power actually gets to the speaker and that running the power through a passive crossover network will "eat" some of the amps power.  Any thoughts?

Thanks