These are amazing speakers!  I have been using the DM 947 monolith for about a month now.  Here's my experience:

I am using a simple 2 Ch setup.  I play digital audio from my MBP to my Wadia 121 DAC to the Torii Mk IV (Aperex 7308's, Gold Lion KT66, Brimar Rectifier) and then through to the DM947's via Kimber Kable 8PR's.

First off, let me say that I am not above using a manufacture's 30 trial.  I have done it several times with amps, speakers, DAC's, you name it.  When I first got the Monoliths set up, they sounded awful.  All I could think about was the cost of return shipping.  I spent some time on the forums, and I was somewhat prepared for this though.  One of the forum member recommended 15 hrs to break in the speakers.  I would definitely agree that it takes at least 15 hrs of play time to be listenable, but it takes much longer to complete the process.  I have had mine playing constantly for the past month or so and they have only improved.  If I had to throw a number out there, I would put a break-in time at 200-300 hours.  After 15 hrs they are listenable, but they are also a bit forward and bright.   It seemed that around the 150 hr mark that the bass started to really come in and then around that 200 hr mark they seemed to warm up.  Bottom line from all of this is that you need to be patient.  These will sound great, but not out of the box.

As for sound these little guys are a bit deceiving.  They look like a bookshelf speaker, but they sound much much larger.  The sweet spot is actually pretty wide.  I was impressed with how I could move through the room and basically still get a good sound.  You should probably think of the Monoliths as being a single driver speaker.  I know that there are two, but the woofer does almost all of the work.  The tweeter in this thing doesn't really start kicking until somewhere around 8 kHz.  The result is that the entire frequency range is really coherent.  The highs are incredibly detailed without being overly bright.  Mids end up being on just this side of warm and the bass is smooth and tight.  As far as I can tell, the Monoliths don't need a subwoofer whatsoever.  I have a really decent Klipsch subwoofer in the house, but it hasn't been used since the Monoliths arrived.  You can try the DM 945's by itself; I did just to see what it sounded like.  The bass was still impressive for such a small bookshelf speaker, but the bass horn definitely extends the range.  Overall, the speaker is extremely detailed and dynamic with a very slight warmth about it.  I always judge a speaker by how well it can play Max Richter's Recomposition of Summer 3.  That track requires both finesse and dynamic power to be "right" and the Monoliths play it well.  

Prior to getting the Monoliths I was concerned that the bookshelf would fall off the horn.  After setup I am not concerned anymore.  The bookshelf and horn are basically a single unit once they are put together.  You can still move them easily enough, but there is no movement between the two, and you aren't going to knock the bookshelf off of the horn by bumping it.  It's sturdy.  My only gripe at this point is a relatively minor one: no carpet spikes.  I like them, but they are definitely not needed for the speaker to work well.

A couple of extra notes about frequency distribution.  As I noted, these are just ever so slightly forward in the 1-4 kHz range.  I was really curious if I could get a better sound through EQ or room correction.  I used both Dirac Stereo and Fidelia's EQ filters.  I messed around with Dirac for hours and hours and the only thing I could conclude is that is crushed the life out of the music.  The measured histogram was slightly more impressive, but it did not sound better.  Fidelia's filters don't crush the music, but I haven't found a setting that I prefer over a flat EQ.  At this point I don't think I would change much about how these sound.  

I know that there isn't a whole lot of information out there about these and I wanted to get my impressions out there for others to use.  I think if there was more info out there on the Monoliths that I would not have waited so long to get them.  You can purchase without worry

Thanks for posting your impressions. I have just purchased a Zen UFO (which sounds amazing) that I have powering a pair of Buschhorns MkII's that I built. They sound great but I am looking for a speaker with a higher sensitivity as Steve recommends to get more out of my Zen amp and these have caught my interest. May have to purchase speaker/base separately. Are these built to order too? How long was the waiting period?

Have you listened to them without the complimentary base?
If so, what were your impressions?