Who manufactures your speaker will also determine whether your speaker is biwireable/ampable. Linn, the manufacturer of my speakers, is really into biamping, and they make the active crossovers and amps specifically for their speakers. Others think that the biamping philosophy is hogwash, like Thiel, and Wilson. These manufactures provide "great" internal crossovers and only one set of speaker connections. (Speaking of great, if you can, you should go listen to some Thiels or Wilsons through a nice system -- You'll be amazed at how good these sound.)

Which one is better? I personally don't know. I've never heard an active system before, but I have heard some really nice sounding passive systems. Personally, I'm opting for buying the best amp, preamp, and cd player that I can afford and hoping for the best. My speakers (Linns, which I bought used) sound pretty darn good through good equipment, although my friend's sound better (VIENNA BEETHOVEN -- sorry for the caps; I copied it from a website) through the same equipment. These two speakers show yet another difference in manufactures -- driver sizes and quantities. My speakers have a single tweeter, midrange, and woofer (8 inch), while the Viennas have a single tweeter, two midranges, and two woofers (6 inch). My speakers have much more ooomph for rock and movies, but the Viennas have much more midrange clarity and have a more laid back but clear bass sound. For stereo, I'd choose the Viennas; for movies, I'd choose the Linns.