Living room system: class A or AB amps?

@tvad 

How high is the ceiling?

It's 10ft to the plaster ceiling, then another 1/2ft to the concrete slab.
I'm about 12 feet away from the speakers.

Regarding doubling down when impedances halves: I think both Pass Labs and Luxman M-900u do a good enough job at that.

If going for Pass, I'd veer towards the X600.8 monoblocks.

@twoleftears

Luxman monos will give you superlative performance. Don't second guess it.

That's encouraging! Did you hear them personally? If so, with what speakers?

@patrickdowns

For watching TV? Okay....

Not just for watching TV. That's just a by-product because it's in the living room. I regularly enjoy long listening sessions, and that's why I'm spending this kind of money.

P.S. I got the newer Stella Evo's. You referred to the older version of this speaker, now on discount.

hey Robert,
I think you know the answer.... its a trade-off of heat, power cost, whether you feel green, and sound.
Lets begin with the fact that being class A vs AB is not the most important determinant of sound quality.  A high-bias AB design does 99% of what a class A design does, at a 75% power/heat/cost savings.  And a well designed AB will sound better. Only when all other factors are equal does the last 1% matter.  keep in mind also that "AB" covers a wide range of bias levels. Either you understand or i cant explain it succinctly here (but am happy to offline).
if you are talking tubes, its a bit clearer, but would one leave tubes on 24x7 anyway? I hope not.
Maybe I'm falling bait to a joke, but listen and evaluate against the practical impact of electricity and heat. I personally cant justify wasting that much power since my amps achieve the vast majority of their warm up in about 30 minutes.  But then again, it was a design goal.
G

To OP, If I had just spent 100K or 65K on sale for that matter. I would think it a no-brainer to jump on a plane and go to the highest of the high-end dealerships who sells Focal and audition amps in a large space. Obviously you're going to spend the dough it takes to get the rest of it correct, meaning to YOUR liking.  Good luck...let us know.
Regards,
barts