Having had ARC tubes for years and also being very familiar with Bryston
(at least the 4B) I would say that they are both good amps, but do sound
different. Those Maggies like current and the Brystons will have more on
hand and will also have a higher damping factor.
Still, there is (to me) nothing quite like the midrange and dimensionality of
tubes. As you know, ARC tubes are NOT stereotypical "warm mid, wooly bass,
rolled back highs" of the tubes of yesteryear. What's more, you might be
very surprised what 200w from tube mono's will do.
As a native Minnnesotan, now exiled in Illinois, I would second the recommendation
that you take the tubes home and try them. I've spend my share of time at
Audio Perfection. Good to hear they're still around.
regards,
Hibuckhobby