Rotel RMB vs. Sunfire Cinema Grand

Hi guys,
After months of searching and reading etc, I have narrowed my selection of amplifiers down to two.
I am very much interested in what a Sunfire Cinema Grand could do in my system. My Infinity Kappa 600s (Front) and 400s(surrounds) are wheezing with the 50-watt Adcoms I have pushing them, and they are bi-wireable, thus the Sunfire, with it's voltage and current source posts for the fronts seems like the logical choice. THey are available here on the 'Gon for around $1,500 used, or less, and $1,699 B-Stock from various dealers such as ATS.
THe Rotel RMB-1075 is not as powerful, nor does it have the flexibility of biwiring, but it would save me roughly $600, and I could buy the Rotel here in town at my dealer, new in box with factory warranty. It would also leave me room to upgrade my interconnects as well.
Can anyone attest to the benefits of said biwiring, and are they worth it as far as musical performance goes? I am a fan of high-rez digital sources, SACD and DVD-A, and of course need the best performance possible in two-channel mode. (The best performance short of Halcro, Theta, VTL, etc!)

Any suggestions would be helpful. I am quite treble sensitive, and many amplifiers sound a bit edgy or bright - maybe a good amplifier will correct the harshness my Kappa's produce at limits of their amps - when auditioned with B&K amplification, they sounded wonderful and wieghty, but were very fatiguing, thus I am not looking at B&K!

Thanks! Happy Listening!

Jon BRown

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