Welcome!
What's a high efficiency class A? Isn't that an oxymoron? Have liked the class A I've heard, and could use some extra heat in my basement listening study, but have never pulled that trigger. My audio roots go back to the 60's, so we must be of similar vintage. Streaming subscriptions of CD quality music is a wonderful solution for access to tons of music.
Am also a point source speaker fan. Currently using commissioned floor standing transmission lines (Martin King MathCad design) that use a single extended range driver (hate to use the term "full range driver" as there ain't quite such a thing, although my speakers come close). The drivers are discontinued Fostex F200a (30-20,000 Hz, 89 dB/w/m, 8 ohm, 8 inch, AnNiCo, no whizzer).
Extended range drivers are the coherence kings, but have limitations. Many such drivers are high efficiency design, but in my experience with high efficiency comes colorations. Small 2-way monitors (with subwoofer supplementation) is the obvious solution. Another solution is coaxial drivers, but not without their issues. Perhaps the best answer I've found is the active 3-way Kali IN-8 that uses a coincidental midrange/tweeter (Kali is made up of former JBL engineers who left after the company was acquired by Samsung).
