With your budget and the amount of space to fill - hands down I would choose either the Sound Lab 845s, 945s or the Maggie 30.7s. Either, when set up properly ( in the location of your red dots would work great - just would have to experiment with distance from the wall behind and toe in) would make a beautiful, well balanced and detailed stage and imaging that would not shift, change, or collapse, regardless of where you are in the room/rooms. Whether seated or standing anywhere near the sweet zone, either would present a very large, deep stage with pin-point imaging and timber to rival any of the speakers mentioned.
The need for massive amounts of power is a bit over stated. I can't imagine any tolerable sound level that couldn't be (with high quality) attained with a pair of Carver, Crimson/Raven 350 mono, tubes or a quality, high current SS amp.
If a low powered SET amp is your thing, I agree that the super efficient, very nice, open baffle, Spatial Audio X3, would be a great speaker for your large room/rooms. Un-rivaled in performance by anything even close to it's less than $8K price tag - would save you many thousands to put somewhere else.
Jim
The need for massive amounts of power is a bit over stated. I can't imagine any tolerable sound level that couldn't be (with high quality) attained with a pair of Carver, Crimson/Raven 350 mono, tubes or a quality, high current SS amp.
If a low powered SET amp is your thing, I agree that the super efficient, very nice, open baffle, Spatial Audio X3, would be a great speaker for your large room/rooms. Un-rivaled in performance by anything even close to it's less than $8K price tag - would save you many thousands to put somewhere else.
Jim