I can only speak from a single set of listening sessions, using Linn gear. I was able to compare three setups: passive biamping using basic-level amps (LK85s), single-amping with a better amp ( LK140), and active biamping using basic amps.
In a nutshell, the three setups came away in the same order. The better single-amp system beat the passive biamp system. The active system came out on top but not by a whole lot. The quality of the amplification was a key factor, so I deduce that a great stereo amp beats out two ordinary ones.
From my experience with these three setups, then, I would say skip passive biamping, get the best single amp you can and when you can afford it, go active with a second high-quality amp.
In a nutshell, the three setups came away in the same order. The better single-amp system beat the passive biamp system. The active system came out on top but not by a whole lot. The quality of the amplification was a key factor, so I deduce that a great stereo amp beats out two ordinary ones.
From my experience with these three setups, then, I would say skip passive biamping, get the best single amp you can and when you can afford it, go active with a second high-quality amp.