Ok. I have it and tried it for my first day.
Take care, I will give an opinion but I only tried it for two hours. I may come back to edit this post in few days.
This is only MY opinion and as I'm not
Sound Structure: Each sound / channel of the ND2 is made by a kind of layering of Tone, Noise and Click generators. Below the sound structure.
Overall sound: Baddcr is right. The sound of this ND2 is immediatly wider, less "boxy" than the MD one (my tip to wide a bit the sound of my MD is pass it through A4 chorus). It takes up the entire spectrum.
Kicks: The ND2 excels in what i call "wet kicks", you know, this kind of soft organic kicks with long decays. I never been able to make this kind of kicks with MD.
From now I wasn't able to make with ND2 these tight punchy matt kicks I love to make with MD. I don't know why, but it seems that there is only 50 tones decay values. Maybe not sufficient to fine tune. I will have to work more deeply on this point.
Snares: Snares are much more immedialty beautiful than the ones I can do with MD. They can be "wet" and soft (808 style) but also very realistic. In fact, I'm very impressed by the "realiistic" snares this box can make. Very organic/jazzy. I don't yet if it can make Punchy/Dubstep snares, I didn't found this kind of snares in presets but this is not a priority for me.
Hit hats, cymbals: As snares, the hit hats and cymbals I can make with ND2 are beautifull, wide.
Toms: They are incredibly realistics, organics, wide. No possible comparison with MD.
Claps: Not very convinced by the claps in presets even when I tried to tune them. But I have the same frustration with MD.
Perc sounds: A pleasure too.
"Synths/Bass sounds": Yes, as the tone generator includes Sine, Square, Triangle, FM generators and as the ND2 can be played chromatically I can say that we can make synths and/or bass sounds. There are a bit "dry" of course and it seems that there is no ADSR filter on tone and noise generators. As there is not way to tune the attack, I think the ND2 can only make synth perc or short time synth sounds. But this is a synth drum...
Hum... My first impression is that Distorsion, Delay and EQ are not the best I heard. But I will need more time to test it.
I though that the "Echo (Repeat)" is able to make a kind of "retrig" effect. This is not the case.
First day: I'm very happy with this Nord Drum 2. I love its wide/organic sound and the possibility to easily play it chromaticaly with a sequencer or a midi keyboard. For me, this is exactly what i miss the most when i play with MD.
Of course, the ND2 has only 6 channels versus the 16 ones of the MD. But as most of the time the drum sounds i like must be designed by layering 2 or 3 channels on MD...
As the ND2 is only an expander it cannot really replace a MD. But as I own an OT too it can be a good alternative to replace my set-up (OT+MD) by (OT+ND2): A powerfull sequencer and sampler (OT) controlling a fantastic drum synth (ND2).
Since today, the midi possibilities of my OT weren't used at all and I'm thinking about adding an Evolver to my set-up which is the craziest analog/hybrid synth I know (I have an A4 and add a tetra). And maybe a Nova Desktop which is very cheap and very good to make magic pads.