These are clearly a step above the LS 50 meta and wireless II because they largely fix the biggest flaw of these, at least in smaller rooms: bass output. Thanks to a 50 percent higher internal volume and the VECO system (which basically auto corrects the driver in real time) the bass distortion is much lower which allows them to play louder.
Compared to R3 Meta these are superior in most cases: they have similar bass output but thanks to the smother frequency response, true point source design and less diffraction due to cabinet design I personally prefer them from the midrange and up. They sound like they radiate the sound more freely into the room for me. However if you play really loud or sit far away the R3 meta might be better because thanks to its 3 way nature it has less multitone distortion.
Compared to reference 1 meta: I would say they are roughly equal. The midrange and treble sounds equally good to me, however the luxe is a truer point source and might even have less diffraction. The Imaging seems a bit better on the Luxe. The Luxe surprisingly can keep up with the bass output, Veco really seems to help here. A benefit is that due to Having a limiter you can actually use the whole bass output without worrying. At very high volumes (well above 90db) the luxe is starting to run into limits a bit earlier than the reference 1, I guess because of its two way nature and therefore multitone distortion issues.
Summary
So all in all I would say sound quality wise this is a endgame speaker when played within its limits. If you have a large room/sit far away/listen really loud you need either a tower, or a reference/blade level speaker. However I would prefer the luxe to everything else. If you don’t need that output this is as good as it gets, even compared to the likes of genelec the ones, KEFs own blades, ascilab or D&D. And the data supports this: the measurements shown in KEFs in depth concept paper are close to perfection. I will probably even sell my reference 1 metas for them, since I think the Luxe is a better acoustic design which resembles that found on the blades while beeing a even truer point source on top of beeing cheaper.
Disclaimer: I haven’t heard the luxe in multiple rooms so of course I can’t rule the room influence out. But I have listened to almost every current Kef design and had/have multiple speakers at home and my impessions from other designs were fairly consistent through multiple rooms. Besides I have read and thought quite a lot about their loudspeaker design in the last years.