Thanks, All, for the feedback.
Honest1-
Much as I like and respect the Spicas, I can't keep 'em now that the Aeriuses are imaging well. I don't have room for them, and money's tight. The Spicas have more of a "Wow!" factor on some intimate vocals in near-field listening, and I'll miss that particular thrill, but the Aeriuses paint the entire front wall with sound from farther away, and that's a strength that's enjoyable on a wider range of material. They're very different listening experiences, but I'm finding that although a few CDs work better on the Spicas, most of the time I prefer the Aeriuses. In addition, the extra money spent on the Aeriuses (twice the price) buys more realistic bass and slightly better detail. For under $1,000, the Spicas are incredible. But, the Aeriuses are over $2,000 and worth every penny. (Of course, I bought used and paid only half those figures.) I hesitate to even compare them: it's like putting Sugar Ray Leonard in the ring with Muhammed Ali. They both punched above their weight, but it wouldn't be much of a contest. They're both champs.
I don't know which model of Audio Physics I auditioned, but they were current models retailing for $3k. Serious suckout in the upper bass, and imaging decent but not comparable to the Spicas.
Slikrik-
As they're on hardwood floors, and I'm too cheap and lazy to go out and pay $50 for brass disks, I'm using pennies with tiny dabs of poster putty to stick 'em to the floor and keep 'em from slipping or rattling. Seems to work quite well.
Doncar-
Although I've never heard the larger MLs, I have no doubt you're right about the advantages of larger panels. Unfortunately, I have a brass wallet to go with my golden ears. The Aeriuses are probably the best speakers I'm going to be able to afford for a long time. From here on out, I'm strictly limited to cheap tweaks. The only thing I can see spending more than a couple hundred bucks on in the next year is the front end. As for cables, well, let me confess that I'm a heretic: I've always been skeptical about claims for expensive wire, and after reading the following articles,
http://sound.westhost.com/cablewhitepaper.htm
http://sound.westhost.com/cables.htm
I can't see spending more than $200 to find out if my skepticism is warranted. The first article, by one of the founders of ESL-maker Innersound, seems to indicate that the ESL panel may benefit from low-inductance & low-capacitance coaxial cable, whereas the woofer will benefit from heavy low-impedance solid or braided cable. It makes sense to me, too, that direct biamping would give the amp tighter control over the woofer more than any cable tweak used with passive biamping would. However, direct biamping of the MLs seems to be a complicated endeavor fraught with peril, so I'm content to sit tight and just enjoy the already stellar performance I've got right now. I'm already enjoying sound far better than I dreamed I could afford, so it feels ungrateful to keep pushing for more.
If a $200 set of cables would make a clearly audible improvement over my Monster XP, I'd be tempted though...
No Money & Barnes-
I'm sure the MLs can take more power. I'm just not sure what I'd do with it. Live levels on even low key stuff like Steely Dan is already running the risk of alienating my neighbors in this quiet prewar NYC apartment building, and Little Feat is definitely pushing it.
Thanks, everybody, for the conversation. I'm having fun both listening and learning. Ain't that what it's all about?