My main speakers are the Stax F-81 electrostatics. Difficult load and brutally inefficient, but with the most refined and realistic midrange that I have ever heard in a beautifully stable and realistic, but small scale soundstage presentation. Love those speakers. When I crave a larger scale presentation with a livelier rhythmic vibe and much better bass performance I rotate in a pair of Paragon Regent transmission line speakers.
Paragon Acoustics was a relatively short lived company that produced some outstanding speakers. The 92 db efficient Regent, with its lead lined interior walls (140 lb ea.) sound like a more dynamic, fuller and more extended version of my Stax. The least “boxy” sounding box speakers that I have owned. They don’t have the beautifully refined and detailed midrange of the Stax, but are not too far off in that respect. I like tomic601’s description of TL’s in general and applicable to the Regent.
*** TL speakers roll off more slowly (less steeply) at low frequencies, and they are thought to provide better driver control than standard reflex cabinet designs,[3] are less sensitive to positioning, and tend to create a very spacious soundstage. ***
As an aside, my Manley Reference 100W triode/200W pentode switchable amps work great with both. Should be obvious which mode I use for each speaker.
Not my pair:
https://www.hifido.co.jp/sold/11-62535-22980-00.html?LNG=E
