Electrostatic pros and cons.

If tech talk is off the table, that's all I have to offer.

@audiokinesis: I think the technical aspect of the ESL is quite important.

The Beveridge lens revolutionized how ESL's sound, especially as it applies to sound dispersement and I'm not sure anyone realizes this but per Roger Modjeski who worked for Beveridge, Harold Beveridge designed these speakers to be placed on the side walls (Duke - recall that RMAF show where the room I was working had the speakers on the side walls - that guy whose name now escapes me worked for Beveridge too and copied the concept using dynamic drivers). The early Janzsen ESLs were also quite unique and the Soundlabs speak for themselves.

Having learned a thing or two from Bev, Roger Modjeski designed his ESLs to have uniform sound dispersement, without curving the panels. In addition, he realized the inherent weakness was in the bass and designed his speakers to be bi-amped with dynamic woofers which he selected to work best at 100 Hz and below. We modified a set of my Acoustat Model 2's using one of his panels (actually a half size version) to go along with the stock panel. I use a 4 box woofer array along with the Beveridge RM-3 crossover to filter the highs and lows at 100 Hz (4th Linkwitz-Riley 24 dB slope with a unique passive EQ added by Roger on the low pass board).

The other major tech improvement we made to the Acoustat's was removing the interfaces. Inherently, Roger felt the step up transformer is the real issue with ESLs. Anyone who hasn't heard an ESL with direct drive amps hasn't really heard what they are capable of. I'm working on taking my ESL 57s in that direction as well. As an aside, and from my perspective I do think the ESL 57 is still the standard by which any ESL is judged (it's what Roger Modjeski used as the model for his ESL), especially when it comes to the mid-range, but I also think people underestimate the bass in that speaker.

Bill, I like your room. Why do you have Avant Garde Duo and not Trio, by the way ? Too big or not much of a difference ?
Coherence is so important.

@inna- uhm, money? at the time I bought the Duo I can’t remember what the Trio sold for, but remember that it needed more woofs to make it right.
I do think the Trio would probably benefit from a decent sized room, especially with those bass horns. I suspect a used pair might be a good deal.
PS: BTW, the room shown in that link is not my main system room, but the front "parlor," a sort of small living room area on the main floor of an old Victorian house. The horns are up in a loft space on the second floor. 

The downfall of ESL's for me is the fact they are delicate and the repair cost is very high if something goes wrong. I had a pair of Martin-Logan years ago and they were excellent sounding speakers. When one speaker started playing at a lower volume than the other one, I called M-L. They said the panels have a definitive life span (like anything) and had probably reached the end of it. So I had to order new panels, and from M-L they only came in pairs, so I could not just replace the one that played at a lower volume. The panels were shipped to me and they were easy enough to replace but the cost was very high. The panels alone were almost as much as I paid for my Magnepan MG 1.6 at the time. Other companies may sell you just one panel and may have different repair options, but this was the real deterrent to me for ESL's in the future. I buy all my equipment used, but I would never buy a pair of ESL's used because of their delicate nature and the repair cost.