Rogue Zues with Vandersteen 5A's at 2004 HE Show

The 5As are designed to be bi-wired, and if you want, bi-amped. Just to digress for a minute, the 3's on down the Vandersteen line are also designed this way. However, with them, the division is between the woofers and the mids/hi's. Since the 5's and 5A's have a powered sub the division is between the mids and the tweeter. There is no speaker wire going to the sub woofer in the 5 or 5A. Which, if I understand some of the above posts, is what is confusing some of you.
When I had 3A sigs. I went from a bi-wire configuration to a vertical bi-amp configuration and the improvement was dramatic. So much so, I would advise anyone with 3A's to give it a try. Since I had the amps available I continued the vertical bi-amping with my 5A's. In this case the difference is very slight and not worth purchasing a new amp to try it.

Themadmilkman,
I certainly hope the article said more then they "sounded like crap", that's not much to go on. Some backround information. I have a pair of Aerial 10T's that I power in the follow way. I am using two BAT VK1000 monoblocks for the botton end(s) and two BAT VK60 monoblocks for the top end(s). This is uniquely "horizontal" bi-amping, and not vertical. Why then would it matter (sound wise) if you used two stereo amps and wired them so that each channel of one amp powered the lows (of both speakers) and each channel of the other amp powered the hi's (of both speakers) verses using one amp for the hi's and low's of one speaker and the same for the other channel. In horizontal, one amp is producing only low freqs and the other amp is producing only the upper freqs. In vertical, one half of each amp is producing low freqs and the other half in doing the hi's. How can one way sound any better or worse then the other?
Swampwalker,
If you are vertical bi-amping (btw, what amp(s) are you using) have you tried to horizontally bi-amp them. If so, how did it sound, if not, why not?
Agaffer,
Aren't the 5's a four way speaker? Since they have a powered subwoofer built in, doesn't that leave the woofer, mid and tweeter left to be powered. So wouldn't the x-over point be between the woofer and the mid/hi freqs and not between the mid and hi as you suggest? In your scenario, the woofer and the mids are combined and the tweeter is separate.
I hope all this isn't too wordy!

Zippyy- I used a pair of McCormack DNA 0.5 Rev A+ (soft recovery diode). I only used them vertically bi-amped, since the designer strongly recommended it. IMO, the primary benefit for vertical bi-amping is increased channel separation, imaging, soundstaging. BTW, I also had a pair of 2WQ subs, so the bass was rolled off below 80 hz, therefore not putting too much of load on the amp in that regard.

Zippyy--

I can't remember his exact words, and don't have the time to drag up the interview again. I've also heard it from other sources.

Thanks everyone for all your input. I appreciate it. Swampwalker, I've heard great things of those amps. Maybe in another system, some day!
Themadmilkman, I apologize in advance if I offend you, but you had time to respond. If you should come across the article in the future, perhaps you could be so kind as to post it, maybe here.
Good luck wilth all your music listening!