Anyone listen to Zu Audio's Definition Mk3?

I received my MK4s 10 days ago. I started with the 1.5, graduated to the 2.0, and now the 4.0. As much as I liked the Def2s, the 4s are a totally different speaker. The only similarities are in size (virtually identical to the 2.0) and looks.

The engineering is amazing. (1) The integrated amplifier can be unscrewed and popped out for service if necessary. (2) Similarly for the bass driver. (3) The aluminum base that supports the downward-firing bass driver is a work of art. (4) The Neutrik Speakon connector preserves the geometry of the cabling and accommodates a selection of connectors for each different type of speaker termination. (5) Bass can be tuned to the individual room. Etc. Everything has been thoroughly thought out.

The highs and lows are more extended. Deep organ notes are palpable (when appropriate). Resolution is better, but the sound is also smoother, more organic, and even a little more dynamic. The soundstage is deep and wide even though they are within 4" of the back wall. Off-axis imaging is amazing; maybe it is the way that Sean set them up on my 24' long wall, but the image does not change whether I am between the speakers, sitting in front of one of them, or standing against one of the side walls. And yet, everything that I liked about the Mk2s is still there. The sound easily fills my living room and the main living space of my house without a change in tone or quality when I am in a different room. I have listened for hours without any fatigue. Truly amazing.

Gsm18439's impression pretty much mirrors my thoughts on them. I have owned the 2's and had the drivers updated to the nano drivers (now speakers are owned by Glory) and that was a significant leap forward in terms of transparency and dynamics while retaining the fundamentals of Zu sound. I spent many hours listening to the 4's after show hours at RMAF and absolutely had to have them after spending enough time dissecting them. For any Definition 2 owner, it is a must have if you can afford them. The bass integration with the downfiring sub vs rear firing will make for much easier integration. More importantly, the bass is so tight, articulate, and palpable compared to the 4 driver array in the 2. It may have been the best bass I heard at all of RMAF. The cabinet is also damped better and has a very solid "thud" when you tap on it with less resonance. The nano drivers are absolutely spectacular and if you can't swing the upgrade to the 4, it's definitely worth the $3500 to upgrade to the 3. The bass amplifier is also much improved both from a modularity standpoint, but also from it's dead silence compared to the hum I heard from the 2's amps. Although it looks like a Definition 2, the only similarities are the spiked feet and the Zu logo. Everything else has been redesigned and this product is a revolutionary, not evolutionary product. When I went to RMAF I had absolutely no intention of upgrading to the 4's but after hearing them, I would have sold a kidney if I had to. I wouldn't have believed the level of performance enhancement of the 4's unless I heard them for myself. I am counting the second until my pair arrives!

As I recall, Zu used split tuning of the four rear firing drivers. While it might have had advantages with that particular configuration, it does not compare to the new single downward firing driver.

The great off-axis imaging (it really does not matter where i sit or stand) as well as the ability to position the 4s within inches of the rear wall were unexpected benefits.

Any more impressions guys? Or comparisons to other Zu speakers?

Zu's facebook page has photos of the new amps going into the MK3