MBL omnidirectional speakers. How do they sound ?

The best system that I've ever heard, (and I've heard many, many, many systems) was the MBL Master Reference System.

Granted at $500K it should be good, but this was just unbelievable and truly a reference.  I will never forget it.

The MBL may be the single most difficult loudspeaker system in the world to set up correctly. I've heard them in Vegas (where rooms are always questionable) sounding both great and mediocre. Then I heard them in Munich in a room suited for them and they were nothing short of astonishing. rcprince pointed out a 'boomy bass'. That can definitely happen, hence the great variablity in their sound. If you room will accommodate them is a real question. In and of themselves, they are wonderful, Highly Reccommended from me. Electronic choice will be critical. 

MBL sometimes demos the 101s at very high volume with a very good, tho unfamiliar, electric blues recording.  At the LAX show, maybe five or six years ago, it was the single most convincing recording of a small combo with  electric guitar that I've ever heard.  Very loud, very dynamic, and tangibly three dimensional.  Nuances in tone aren't going to be front and center in that type of demo, but there was nothing distracting about those characteristics.

However, I've also heard them at a few dealers where the tonal balance has always been an issue.  Especially in smaller demo rooms, the bass can be a little much and the presence region a bit forward.  I was actually considering a purchase at one time, but held off because I feared that my room was probably too small to get proper bass balance.  Even then, I thought hard about possibly bypassing the internal woofer box in favor of stand-alone subs.  Eventually, I decided to pass.

In all, I find that the 101 is among the truly great speakers that I've ever heard, but they really need a large space to sound right in tonal balance IMO.

BTW, I found the smaller MBL floorstanders much less impressive.

the whole room is fill with sound. one drawback is the image location & depth of field are not easily recognisable

They require lots of power and current.

Agree. Used to own MBL but gave up on them.
They are very different from my current speakers, VA The Music.

I heard the 101e's twice at shows and each time thought they were excellent but each time they were in larger rooms. I think they wouldn't work too well in a small room, they need a big room to really shine. But properly set up they are in my top 5 speakers that I've ever heard.