Two Sunfire Signature's wired together?

I've used two Sunfire Signatures bi-amped with two different sets of speakers and the results were very different for each set of speakers.

I first used a pair of Sunfire Signatures to bi-amp a pair of Infinity Kappa 9....very inefficient notorious hard-to-drive power hogs. Bi-amping the Kappa 9 were a world apart from using a single Sunfire Signature amp. The improvements were dramatic.

I then bi-amped a pair of Infinity Rennaisance 90 speakers.
It was a complete waste of an extra amp. Bi-amping was indistiguishable from using a single amp with these speakers. They are much more efficient than the Kappa 9.

Regarding my post above:

I used a vertical bi-amp configuration in my setup. One amp per speaker.

At present I am just using one channel of each Sunfire to drive each speaker. It's not bi-amping, but each speaker is receiving the full 300 watts with the power supply which normally drives two channels driving just the one whcih gives it a bit more headroom than if I used just one amp for both channels.

What I will do once I rewire the speakers will be to use one amp vertically for each channel. Basically, I will connect the preamp to each signfire unbalanced with the highs (ribbons) receiving the Current outputs of the left channel and the woofers (through the active crossover) receiving the voltage outputs of the right channel. I then will do the same for the right channel with the other Sunfire.

Traditional biamping would have one unit drive the highs and the other the low signals. By having each amp drive both the high and low signal of one channel you get the same benefits of traditional biamping, but the amp sees both sets of drivers and therefore is more stable. The ribbons get the high current and the woofs get the high voltage. Perfect!

I have an old Audio Control x-over that I'll try unbalanced vertically and a Rane AC23B balanced x-over that I'll try using the Sunfires in a traditional bi-amp configuration and see which is best. I also will try my Ciounterpoint Natural Progression mono blocks on the ribbons and a trusty Sony TA N80ES on the botytom and see if that works better than the dual Sunfires. I also might try the Counterpoints with pone of the Sunfires on the bottom tocover all the bases. Then I'll sell the gear that doesn't make the cut.

I currently have two Signature 600s in my system, which has balanced interconnects. I simply run one channel through each amp, without bi-wiring or bi-amping as described in the Sunfire manual. The speakers have only one set of binding posts. (I have separate subwoofers powered by their own amps.) My understanding is that this method uses all of the power of each amp for each channel, so I am wondering what additional benefit there would be to the wiring methods described in the Sunfire manual.

Has anyone compared the simple double-amp method described above to the specific monoblock instructions in the Sunfire manual? What were your results?

btw: As noted in another thread, using two 600s is far superior to two 300s.

Yes! Two Sig 600's, (mono bi-wire) Classic tube pre, Martin Logan requests. DYNAMICS redefined! I added two vintage Magnepan MG 1b's to the remaining current outputs for kicks. Holy crap. Then added a vintage dbx 3bx ds, with all power connections to Tice Power Block/Titan units. This audio gig is a blast.