Speakers that disappear

I have been listening once again to mbl 101-Es last weekend and have been very impressed by the great illusion they create just by "disappearing", i.e. I could not localize the speakers with closed eyes.

Listening to these speakers got me interested again in speakers that create a large 3-dimensional image, "disappear" and do not sound "boxy" in the low frequencies (with boxy I mean that the base somehow sounds constrained by the loudspeaker enclosure, especially the massive drivers in the B&Ws and Kefs gave me that feeling, the very low frequencies had a slightly "wooden" sound to it - I listend to Richard Wagners Valkyrie amongst others and drum strikes suffered in particular).

[I am obviously aware that there are many other characteristics that are required to make a great speaker, i.e. transparency, etc. but i would like to focus on the above in this thread.]

The only two speaker brands I have listened to that did the trick in this respect for me are:
- mbl (the 101-Es, dont know if this applies for their smaller speakers)
- Wilson Benesch (ACT and Chimera, not as strong as mbl but still pretty good - unfortunately a bit too week below 40hz, even the Chimera)

In comparison listening to Sonus Fabers, Kef References, B&W 800Ds, Ayon all of them sounded "boxed in" in the low frequencies and the sweet spot was much smaller and perfect toe-in was far too important for getting a decent image and illusion. (I know these speakers do some other things very well so no need to mention)

Now there are a lot of other great speakers that I could not listen to yet. Therefore I would love to hear some opinions about the ability of some other speakers to create an illusion by disappearing and not sounding "boxed in".

One type of speakers that do a good job in the above seem to be planar speakers but I have listend to both Martin Logans (dont remember which one as they all look so similar) and Magnepans (1.6 if I remember correctly) but somehow they did not do the trick for me and while they disappeared the soundstage sounded a bit flat and lifeless to me. (Both were driven by McIntosh Pre and Monos).

Particular speakers I would be interested in are:
- Magico
- Wisdom Audio Sage Series
- Rockport

At this point I prefer soft dome and paper/carbon type drivers and have not been a fan of ceramic drivers, beryllium, diamond or aluminium tweeter (in those implementations that I heard). Nevertheless there may be great implementations that do the above very well, so I would also be interested in opinions about:
- Kharma
- Focal Utopia Series
- Revel Ultima

Also are there any mid-price speakers that do this well?