Thanks for the responses gentelmen.
As for "which came first", I think the amplifier is AS important as the speaker for making good music. I don't think any speaker could sound good if the amp was passing junk forward.
What impressed me in the Harbeth room was a sense of precision coming from the monitor. A sense of absolute control that translates into a clearer sense of the event being recorded.
I've heard others say that tubes tend to homogenize the character of a system so everything you play feels the same.
My concern is that, while impressive in the short term, the SS effect may be fatiguing in long listening sessions.