OK, I got one!
To be honest, I have spent VERY little time on it... but here's a preliminary review.
I opened the box yesterday afternoon at 3:30pm and gigged with it at 6pm! All I did to prepare was change a few pad assignments on my ZX to match the DM10's mapping (which is NOT in the manual, by the way... MAJOR oversight!) and I ran through each of the 100 kits to see which ones I liked and for what. I didn't change any instruments or levels, etc., just took it to the gig.
The first thing I noticed was that it was way less "hot" velocity-wise than BFD, which required me to play differently. Not a big problem, but I really had to focus (today I messed with the DM's "Vel to Level" parameters and it's really an effective adjustment for this issue.) I wish the DM had BFD's velocity window!
The sound was very, very good. Not BFD-good, but the best hardware module I have heard yet. I really liked the ride cymbals especially, and there's a set of 5 Yamaha MCA toms that I love. Snares were hit-and-miss IMO, but I found several I really liked. I didn't find a cross-stick I liked, but with some tweaking I have a couple that work. Hi-hats were a problem for me: I only found 2 I liked, and each required pitch adjustment to sound realistic. Most of them were completely unusable for me. I have not yet figured out how to adjust the volumes of different articulations (like pedal chick) individually, but I hope it's possible. Crashes were good, splashes few but 2 were good, really good chinas, percussion samples are great, but I didn't find a cowbell I loved... still tweaking. Bass drums were the weak link on the drum sets... lots of them sounded canned to me, especially in the lower velocity range. Alesis's "dynamic articulation" (i.e., multisampling) is really awesome for a hardware module, but not even close to the detail of BFD. But it's a nice compromise.
One thing I really liked was that the levels of the instruments in the kits worked really well right out of the box. I hate when you use a module where the levels are inconsistent within the kit or between the kits; this was great in that way. The factory kits were well-put together, well-mixed, and well-named (I knew what to expect by the titles.) When using hardware modules, I like that you can call up a sound, and it sounds good immediately. You don't have the precision control of software, but the upside is the instant (if limited) gratification.
Today I spent some time building my own kits, and I really like the way this module is adjusted. I have always preferred Alesis's architecture over Roland's; the DM10 seems to incorporate the "openness" of the old Alesis modules, with the graphic interface and menu systems like Roland's. I did not need the manual at all. (The only thing I looked in it for, a midi note map, was not even in there!)
The FX are OK, the room simulator is pretty good, and the EQ is lame... a simple hi and low parametric. I would love a 4-band parametric or a simulated 30-band graphic.
Bottom line: I liked, if not loved, enough sounds to make this a totally usable module for me. I LOVED some of the sounds. The premade kits are very good, the editing architecture is user-friendly, I have not found any "why can't I do that?" issues yet, with the possible exception of HH artic editing (update to come...). The price is right, the convenience rocks, the kit load time is instant, etc. I give it a 9 out of 10 overall. No, it's not BFD-in-a-box. BFD sounds like a real kit because, in essence, it IS. But there are advantages to modules: I loaded in last night in ONE trip (amp included), was set up in seconds, and had a great gig, even on the factory kits. As a "lite" rig, I am very pleased!