Bi-amping Vandersteen Treo CTs

So I just got a VTL IT-85 integrated amp and am very happy about the upgraded sound with the Treo CTs when compared to the previous amp, a Cronus Magnum II. But reading the VTL manual tells me it's possible to bi-amp by adding their ST-85 power amp, which seems appealing.

Here's a quote from the Vandersteen owner's manual:

The only way to properly bi-amplify the Model Treo is passively, with two identical amplifiers in a vertical configuration. (one stereo amplifier per channel) An electronic crossover cannot be used since the crossover in the Model Treo is not bypassed. The result would be two crossovers in series creating severe phase shift. The use of two different amplifiers or an electronic crossover will negatively affect the sound of the speakers and reduce their overall performance level.

Here's VTL's take on the matter:

The best example of this type of bi-amped system would be the use of the VTL ST-85 stereo power amplifier, which has been precisely gain-matched to the signal that will be output from the preamp outs of the VTL IT-85. It is recommended that for this type of system the amplifiers get connected to the loudspeakers in a horizontal (rather than vertical) bi-amp mode (i.e. with one stereo amplifier on the bass of both channels and with the other stereo amplifier on the top of both channels). In this fashion the IT-85 becomes the central source director and volume control for the whole system.

So who's right?