abnerjack --
The potential of the LaScala’s is relative to a combination of factors which may deter somewhat from your present situation. A significant impact is your first listen which, as you already proposed, would take place in different surroundings and with different equipment. I’d wager you should still be able to gain some rudimentary understanding of the sonic abilities (and character) they possess. To get from here to a decision with regard to purchase may take a leap of faith, and if such a decision is made (or even prior to it) you would have to consider achieving their fuller potential; my first step here would be towards the right amplification which could include SET’s, SIT’s (solid state) or any single ended low wattage class-A solution (SS). At least as important would be considering a more widespread refurbishment of the LaScala’s themselves with the aid of the likes of ALK Engineering. What’s entailed here is new drivers for the mids and tweeters with new horns, and crossovers. Perhaps it might be preferable updating the bass drivers as well (from Bob Crites) being the pair you’re looking at are some 40 years old, but if they sound fine here I see no reason than to simply maintain them as they are. I know this refurbishment sounds radical, and it would add a significant expense, but this way you would come to avoid the shrillness or harshness some have reported to find in the original speakers, combined with a fuller, more effortless and rounded (i.e.: natural) sonic presentation.
You may have heard of US-based Volti Audio (who are also delivering upgrade kits to some of the Klipsch Heritage models) who are known for the Vittora model, which are from-ground-up built speakers heavily inspired by the LaScala’s. Reading reviews of them would give you an idea of the level of sonic potential following a refurbishment of the LaScala’s. Myself I own a pair of Simon Mears Audio Uccello’s, which are from-ground-up handmade speakers based on the Belle Klipsch (the "Belle" version of the LaScala’s) - the UK equivalent in a sense to the Vittora’s, but not sonically similar - but with different midrange and tweeter drivers + horns and crossovers compared to the Vittora’s. A review of the Uccello’s can be found over at Dagogo.com, which would also give you an idea of the sonic potential here.
Going by the Uccello’s you get a very coherent, dynamic, effortless, and crisp yet warm presentation. They’re very present-sounding and still easy on the ears. The overall presentation strikes one as an encompassing, lively-vibrant sphere. Their signature is grounded in the upper bass/lower midrange which seems to define the sound with a more resonant and rich presentation than found in typical direct radiating speakers, and this is where listeners are divided - at least as an outset. I find this to be both a character and a quality, for most speakers seem to rid the sound of an important energy and timbre found in live music in this particular frequency range, going instead rather anemic, lean or even bleached. What amazes me again and again is their prowess with classical music; piano in particular sounds more real and alive than most other speakers I’ve heard (and I’ve heard quite a lot), as does jazz in general - not least the saxophone, which is almost scary in its unrestrained there-ness, dynamics and natural tonality. Music seems un-covered. Studio productions are a mixed bag - the morphing soundscapes here vary wildly, from outright underwhelming and collapsing to rather natural and open. The sonic manipulations at play here borders the crazy. One area perhaps to emphasize with the Uccello’s is their midrange, which is downright spectacular. Forget about them being horns. Play them hellishly loud and they are absolutely stoic and fully at ease; play them low volume and yet they are informative and alive. The insight, cleanliness and naturalness of tone is something to behold. The bass rolls off quickly below 50-60Hz, but is tuneful, enveloping, and agile. Add subs if finding them too lean here, but not just any sub.
Sorry for the long post. Finally someone wrote about horns of the likes one can at least partially relate to. Hope some of what’s written here is useful.