I have heard them and they are one of the most impressive towers I have ever heard.
As I have stated a few times in other threads, a pair of these {with the regular tweeter, I have heard them both and prefer the std tweeter, although the ribbon is awesome, I think the std tweeter sounds better with the music we were listening to}, with an HSU uls15 dual drive, an Emotiva XLS1, and an Emotiva XPA2 is one of the best bang for your buck systems available, for $6000 I will put it against anything costing much more.. I have heard systems all over the world {OK all over the US and a few in Europe
and that arrangement of components did it all, the bass was fast and deep, the mids and highs were as perfect as I have ever heard defined warm with zero fatigue, you can listen to them speakers all day.. Plus the versatility was amazing, from old recordings of Satchmo's what a wonderfull world to Eminem's Lose yourself the setup did everything perfect, we listened to Aerosmith, Bruce, jazz tracks from 80 years ago, and then someone started a track by Timbaland called Apologize and although its not my favorite type of music, the digital sounds and voice was mesmerizing it is now one of my "test your system songs" along with Sinead Oconnors rendition of silent night...
If you want something warm, realistic, strong, defined and a pleasure to listen to for hours, the Ascends are your guys, I hear really good things about the Phil 3s but the looks of the cabinets kill me, and I have heard from 2 people I trust in the audio field that say the sierras sound better {with Ribbon Im not sure if they ever heard them without}....
We all have our preferences, For music I prefer 2.2, I have tried a few other things, but to me if you want something that "does it all" you want a decent speaker crossed around 70-100 high pass and then at least one sub to handle the low end but 2 seems to make the system easier to tune for some reason, seamless....
I came across this combo after I already built 2 2.2 systems {one is in my formal parlor and one is in my guest houses living room/bar area} both of which make me happy and sound great, but my next one is going to be what I described above... We have A LOT of guests over very often, and when ever I play my 2.2 systems people are impressed, that is actually how I got to listen to the ascend /hsu combo, a couple of friends of mine wanted to upgrade their 2.0 systems after hearing mine and went to what I recommended, so I got the fun of hooking them up and listening for a good long while.. A good friend of mine {I baptized both of his children} has the system and when ever we are there, I plug my phone into his dac and throw a playlist on, I can not get enough if it... Someday I will upgrade but if my wife sees new speakers come in the house any time soon I am going to be outside looking in, we have at least $30K in audio equipment, lol... I recently picked up a set of Carver Black beauties I have no idea what I am going to do with but the price was so good I couldn't resist $4500 brand new never opened for a pair !!!!