Yes, I totally agree that there are benefits and trade-offs to a tightly integrated active solution and separates/passive speakers etc.
One of the challenges in placing a speaker very near wall is that you get cancellations in the response based on the quarter wavelength distances to the nearby room boundaries that occur in the critical time window if integration (2-5 ms) where they are perceived as the same acoustic event as the direct sound and so cause a tonality issue. To the extent that there are early reflections laterally, this can cause issues in mid/higher frequencies as well.
There is also the issue of boundary reinforcement where you get nearly 3 dB (in practice, closer to 2 db) per boundary of shelving up of the bass and lower midrange response.
The Kii and Dutch&Dutch unique in their directivity control to significantly address the former issue and have some facility to use the latter to help with some of the dynamic challenges in a smaller speaker.
In our case, I’m implementing a boundary control, not dissimilar from what you see on some of the Revel speakers and a number of studio monitors. This works well for correcting the bass/low midrange level and integration and correcting for the boundary reinforcement but there are still issues with a cancellation off of the front wall for all speakers with traditional LF directivity (basically everything except the aforementioned models).
I wouldn’t say that our entire speaker strategy is based around near-wall placement but we are trying to give some level of adjustment. The speaker are physically rather deep and you only need to get them a little ways out from the wall to get the front baffle to where these reflections are perceived as ambience and not coloration.
Also, some basic treatment (like a 4" absorption panel behind the speaker spaced a couple of inches form the wall) that is effective in the low midrange and above, could be employed for apartment dwellers or folks with severe placement limitations.
As far as sealed box (acoustic suspension) woofers go, they don’t actually benefit close to the wall more than a passive radiator or vent. Where they benefit is that you are acoustically “near” more and more boundaries as frequency decreases and so, depending on how rigid the construction is, you’ll see a boundary/vessel “room gain” at very low frequencies that approaches 12 dB per octave below roughly 2X the wavelength of the longest dimension of the room. This matches up well with a sealed box roll off (if the speaker extends deep enough), as you get something like 6-10 dB at 20 Hz in a typical room.
That being said, a sealed box speaker is 3 dB less efficient for a given low frequency cutoff and a reflex system (like a port or PR) causes a cone minimum at tuning (the cone basically doesn’t move and is held still by the box pressure) and so distortion is much lower and you gain about 6 dB of maximum output in the 1.5 octaves around resonance. If the tuning of the system is set low enough (not a traditional maximally flat alignment), you can still take advantage of this room gain with a PR etc. because you’re changing the shape of the “knee” where this speaker/room gain combines.
Also, user preference typically isn’t “flat” in the bass and something in the range of a 1 dB per octave
tilt in the power response is preferred (with as much as 3-10 dB of additional LF emphasis below 100 Hz depending on if people are trained or untrained listeners). As such, some sealed box or dipole systems can sound “tuneful” and “tight” but a little “lean”, depending on how they integrate.
I’d say Focal musical, Harbeth coherent, Wilson technically revealing.