All these wonderful SET systems...I'd love to experience more of them myself, like the 2A3, 45, 805 et al. I've only experienced my own 300B SET amp with matching 6SN7 SRPP linestage pre (from a designer/builder in Hong-Kong), and I too am sold on that heavenly, magical midrange.
And according to my less-than-golden ears, not only do SETs sound so fabulous with single-drivers and horn-loaded loudspeakers (like my present Klipsch RB-75 2-ways and former Loth-X transmission-line, alnico-magnet Amaze), but also with my 91dB efficient Triangle 2-way Zephyr towers. These unlikely cones 'n' domes love my 6.5Wpc SET amp (in my tiny listening room) and sound rich and clear with full-bodied bass (without my two Dayton subs powered up)...it's stunning the clean low bass I can capture with these French made beauties with the 300Bs. If my system was in the much larger livingroom, I know I'd need more power than my SET amp can provide. But for now I'm stoked...I can only imagine what massive Tannoys and VOTTs would do (the closest I had were my dad's old Klipsch Cornwalls, and that was sweet indeed)!
Happy listening.