I will be doing a proper write up once I receive my 9.87's (although the fact that I phrased it that way should tell you something about what my answer was
In another forum, someone asked the same. Below is my response (and to try to stay on topic here, I'm sure the Hugo2 would be able to drive the 4D drivers to amazing levels, but I haven't had a chance to try that configuration yet)
(tl;dr - Omega : Voxativs == Mojo : DAVE)
Completely different level of sound. I adore my Omega SAMs. The Omegas opened my eyes to what was always there in the music, but that I never had the kit to hear. It was like the character in Flatland that is lifted out of the 2D space, and can see 3D for the first time. Once you hear it, it is impossible to go back.
The Omega direct was one of several "Red Pill" experiences for me over the past year (review links below). One of the other Red Pill moments was when I first heard the Chord Mojo. Absolutely stunning, dollar for dollar the finest DAC on the planet. Blew me away. Based on what I heard, I ordered a Chord DAVE unheard, and right after I heard the DAVE, the Chord Blu2 unheard.
I'd say the Voxativ 4D drivers ($15k for the pair, then you have a variety of cabinet choices to drop them in) are the DAVE to the Omega Super Alnico being the Mojo: takes what is transformational in the Omega alnico's and makes it effortless and vast, with stunning new detail and speed, tonal balance, and virtually no distortion. The price of the Mojo to DAVE is also roughly the price of the Omega driver to the Voxativ 4D driver. I suspect some of the Voxativ hybrid field coil drivers may have Blu-level impact, but I'm not willing (yet
to drop $65k a pair(!) to see what they can do.
I was hearing things through the Voxativ's and BluDAVE that I hadn't heard before. The Voxativ 4D drivers were 103dB sensitivity, so the DAVE drove them with pretty unambiguous authority. I was enjoying the BluDAVE too much to drop in BluHugo2 to see how it would drive the units, but based on the room shaking levels we got to, I'm sure even the Hugo2 could hold its own with these speakers.
I also had a chance to spend a couple hours with the incredibly impressive Voxativ T211 tube amp ($20k). As amazing as the Voxativ T211 tube amp was (by far the finest synergy between tube amp and transducer I've ever heard), as I and others have discussed here and elsewhere, no amp on the planet can hold a candle to the DAVE (or Hugo2) driving high efficiency speakers direct. That being said, the Voxativ T211/4D combo was the smallest gap to DAVE direct I have ever heard, which says a lot about the engineering prowess of the Voxativ team.