Monoblocks vs Vertical bi-amping vs Horizontal bia

In attemps to raise the sonic bar of my system, I'm considering my options which includes using a single stereo amp, mono blocks, or 2 stereo amps in either a vertical or horizontal biamped configuration.

Q1: Who out there has experience in how each of the above scenarios differs from one another. If you read Dennis Had's article on vertical biamping at his Cary web site, you'd think that that is the way to go but how does this differ from monoblocks which accomplish the same thing (i.e. one amp used per channel for all frequencies)?

Q2: In which situations do the various amp scenarios best lend themselves (room size, listening levels, speaker sensitivity and ohm rating etc. etc.)?

Thanks for your input.

Kevinzoe