Best realistic omni type speaker option?

I have a pair of Martin Logan Ethos at home that sound good, and Davone Mojos at the office which for their size make great music too. 

While I like the MLs a lot, the sweet spot is small. A foot to either side and you're not getting the best sound. Which is why I'm interested in testing an omni against them.

But here's the thing, which to try at around $4-8k?
  • Ohms - lots of fans - basically a cone speaker mounted in above the cabinet and firing down with a tweeter on top- reasonably priced
  • Duevel's - upwards firing woofer with downward firing tweeter above - Bella Luna horn loads the tweeter - expensive and hard if not impossible to get in the U.S. 
  • Decware's HR-1 - hybrid omni / box speaker design  - 5 month or so wait 
  • Or since I like the MLs, step up the line to a pair of ML 11a 

There is a pair of Ohm Walsh 5's here for sale (black piano finish). I have an older pair of the Sound Cylinders. Room-filling 3-D sound! Better than any ML!!!
Second on the Duevels. Never really warmed to Ohms although my exposure is limited.
cdc2, you are already use to ESLs. MLs are limited because of that curved diaphragm which forces ML to go down at 250 Hz to a dynamic woofer smack in the middle of the midrange where ESLs are supposed to shine. The curved diaphragm is not linear. Roger Sanders, the inventor of the curved panel abandoned it for that reason. If you go to any form of dynamic speaker you will lose some clarity and detail not that there are fine speakers out there. My favorite right now is Sonus Faber. They make a great speaker for the money. However there are two choices that will give you better dispersion and improve the level of clarity and detail you are use to. The Magnepan 3.7i and the Sound Labs 545. They are bigger than the MLs so I do not know if they will work in your room. My favorite Dynamic speakers are Sonus Faber. They make a great speaker for the money. Upscale Audio has a pair of Olympica 2 speakers on sale. I have listened extensively to the Sonetto 8. Very smooth. No harshness in these. They do very well w/o a subwoofer, but you could add one if you really needed power below 30 Hz. They have as good an image as any dynamic speaker which means the cross over is very high quality. On top of this their cabinetry is first class. 
I personally prefer the sound of planar dipoles specifically ESLs. You get a larger image and a better sense of the third dimension. The Magnepans which are planar magnetic and ribbon speakers have excellent dispersion. Their tweeter ribbon is unmatched. But, they are not quite as detailed and their image although excellent is just slightly out of focus when compared to a full range ESL. 

Good luck,
I have commented about this topic on other threads before.  All the omnidirectional speakers you listed have their advantages and weaknesses, like any other speaker.  One you should add to your list is Larsen, made in Sweden.  They are a modern version of the old Sonab speakers.  I sold these for a few years and customers love them.

I love classical music and now that we are empty nesters I find myself listening more to classical music of all types. My Coherent and Omega single drivers are great for small ensembles but can't quite pull off large orchestras and complex music. Zaftig mezzo sopranos wearing horned helmets on the women on single drivers? Naaa (a technical term of rejection).

Having said that, I just purchased a pair of completely restored Shahinian Obelisks and I'm blown away at how wonderful they sound.  I had heard Obelisks years ago and files them away in the "good speaker" compartment of my brain.  I bought them on a whim and after a week I'm sure (well, pretty sure) that I will keep them forever.  AND my wife actually loves the way they look; or at least that's what she says but she also has been hinting about a new car...

I don't have recent experience with Ohm or Decware and I don't have any experience with Duevel.  But my summary comparison to the Larsen 6s or 8s is that the Shahinian Obelisks present similarly but more so.  The Larsens painted a large sound picture on the wall behind the speakers, in bright watercolor paint.  The Obelisks are much more 3D (some say holographic) and the picture is painted in oil and has significant texture.  Right now I'm listening to Isaac Stern and the New York Philharmonic play Beethoven's Violin Concerto in D Major.  I am very familiar with this piece of music and it's like I'm hearing it for the first time.  I played some other stuff earlier today: jazz, bluegrass, classical guitar, Grateful Dead - all great.  I haven't tried Nine Inch Nails yet but maybe tomorrow.