I had the Theta's and they sound pretty much the same as your description. Biggest soundtage I've ever had.
Mark Levinson 436 vs. Theta Citadel monoblocks
I'm thinking about to get either one of these to match Dynaudio S5.4, I know they are both good amps, can't decide which is better for S5.4, I like a slight warm sounding, but still with details, big sound stage, not too forward not too laid back, any members had them before? thanks!