@pauliG
I’ve read some of the same thread over on AVF, and I’m not going to answer it there as I want to say there’s a lot of BS being banded around by people who have no idea what they’re talking about.
KEFs lend themselves very well as a replacement for a soundbar, as the wide and evenly dispersal of the sound from the point-source UniQ driver allows a larger sweet spot. Many conventional speakers will have quite a narrow sweet spot, so when you sit in the middle, you can move your head a few inches from side to side and the whole balance falls apart. KEF speakers hold it together over a wider area, ideal for more than one listener/viewer.
With regards to the likes of LS50 Meta and R3, and partnering them with smaller amps like Sonos and Bluesound, I personally wouldn’t. It’s ok for background music, but these aren’t really background music type speakers. These speakers need plenty of power and control, and will only sound as good as the accompanying amplifier will allow them to. And don’t allow sales assistants to demonstrate speakers like this to you on the end of £2k amplifiers, where they will sound great. Listen to them on an amplifier within your budget, otherwise it’s a useless demonstration.
How big your room is isn’t so much of an issue if you’re sitting fairly close to the speakers - the most important thing is the direct sound from the speakers and how far that has to travel.
And while the Q350 isn’t as good a speaker as an R3 or LS50 Meta, it will be a better match for the Sonos and Bluesound amps you mention. Theyre an easier load for an amplifier to deal with, and the less you tax the amplifier, the better it will sound.
As far as the Sonus Fabers are concerned (as mentioned on AVF), have you listened to them with movies/TV viewing? The last set of SFs I heard were way off the mark with movies. Probably fine for music, but not movies. Not for me anyway.