I am the very-happy owner of the Linkwitz LX521.4 system for almost 10 years now. For me, this is my end-game: the spacial and smooth presentation across the entire frequency band is to die for. You can see my system here: https://linkwitz.store/blog/2023/01/20/new-linkwitz-lounge-in-fremont-ca/
I am NOT a dealer by any means: I agreed to open my home to interested audiophiles, because I am convinced that - once you hear it for yourself - there is no going back to anything else, particularly in this price range. If you are good with your hands, you can built those from an IKEA-like pre-cut flat-pack (that's what I did), saving you about $5K (and have your choice of finish: mine is Lexus Pearl White automotive coating). Note, however: you will need to buy the entire system, including the two PowerBoxes: each Linkwitz driver has its own (ClassD, Hypex N-Core) amplifier, 5 per channel (250W x 2, 200W, 150W, and 100W for the tweeters), which comes to 10(!!) amplifiers total; moreover, each channel has its own active crossover, making sure each driver operates only in its linear frequency range. As said above: the result is a mind-boggling being-there illusion. All you need is a good preamp/phono stage (if you spin vinyl) and/or DAC (I use the impeccable MSB), and you are ready to go. I use a tube preamp/phono stage (Supratek Grange), which gives me the best of both worlds in terms of smooth mid-range and punchy authoritative bass. If you happen to be in the Bay Area, feel free to set up an appointment!