Update:
After tweaking and spiking, the Aeriuses are now sounding really terrific, with central vocals that are as focused, if still not quite as solid, as the Spicas. I pulled the Aeriuses another 3" from the front and side walls (39" & 27"), toed 'em in a tad more, moved the listening position back a bit, and replaced the slider feet with spikes. Man, I was surprised at what a major difference the spikes made. It was not subtle. The imaging, spacious but fuzzy before, became spacious and razor sharp. These babies are cookin' now, and they're equally good on intimate material and big-stage material. I think the Adcom amps are a perfectly good match. But, then, I've always tended to favor a slightly bright sound, a la my Stax Lambda Pros.
All this doesn't make the Spicas any less impressive. But, I'm now very happy to have the Aeriuses and have no regrets about replacing the Spicas with them.