Dhartwick -
Whether exchanging your Bel Canto poweramps will get you to your desired goals - i.e., more "speed and overall realism" - is debatable. Then again, maybe a pair of NuForce Ref. 18(soon to be 20) mono's could very well do better here. NuForce's Ref. amps in general are known for their great abilities (among other virtues) into speed and timing, which I can attest to owning one of their poweramps myself.
Moreover, I'd go the "less is more" route and get rid of your preamp, and invest in a new and combined DAC/preamp - maybe even the Bel Canto DAC3.5, which I've heard houses a splendid build-in digital volume control. I'm sure there are other very worthwhile DAC/preamps alternatives as well - that would also better your Bryston as a stand-alone DAC - as long as it gets the separate hardware preamp out of the way. To my ears separate preamps in general robs the sound of see-through(transparence), texture, and dynamics - where a good "substitute" DAC/preamp solution is found instead.
Why power filtration? Maybe I should ask which kind of power filtration you use? In general I find power filtration to flatten out the sound and rob dynamics, just my oppinion. A good star-grounding and dedicated outlets/power group should bring you a long way.
Cables: I'd avoid heavily shielded cables - be they IC's, speaker- or powercables. Heavily sheilded cables in my ears dulls the sound as if putting up a filter between me and the music. Also, I have an affinity for solid-core wires and finds it actually makes sense to speak of this aspect in a general fashion, in whichever combination they're used; an overall cleaner, tighter, and more physical sound.
Sorry if I'm coming off sounding "this way and none other" - that's not my intention.
