Sorry this post comes too late to be useful to you. But I guess I'll chime in anyway and hope that someone someday might find this helpful.
I played a NU1 in a local store some weeks ago. Didn't like it - basically there's no control over the volume from pp to mp, like hmfadopter mentioned, a slight trigger (slightest increase in force) would push the volume up the roof. I am quite sure it's the action, nothing to do with the damper pedal, or me.

But that piano did look like it had taken some bad beatings from passers by and customers so I assume it might have been an out-of-regulation or a faulty action after taken too much abuse.
Today I had an opportunity to play an all new NU1, it was just shipped to Hong Kong and just arrived in the shop today, and here are my impressions.
The sound.
It is beautiful. Simply wonderful and one of the best I've heard for digital pianos.
The Action.
It is terrible- nowhere close to a real acoustic piano, which is such a shame considering how much work has gone into it. Here's what I think are issues leading to the poor action:
1. Leverage problem.
The keys are on the "light" side but I think it is not helpful to talk about "lightness" or "heaviness" of this or a Clavinova/ Roland etc without considering the physics of the key mechanism. I haven't taken the NU1 apart but I can imagine that the key is somewhat short (esp. the part beyond what is visible). So what happens is, it takes a harder press at the back of the key than the front of the key to generate a sound of the same volume. As a result, it is "light" in front and "heavy" at the back of each key, which makes it very different from an average upright and this unevenness makes it hard to play passages with sharps/ flats (not even Moonlight 1st movement).
2. Non-linear response between finger pressure and sound volume at lower volumes.
As mentioned above, very difficult to control the volume between pp and mp, as I found out today this is apparantly a characteristic of NU1 and not due to an abused unit, making it pretty useless for playing or practicing soft music like Moonlight sonata (1st mvt) or Chopin nocturnes.
3. Inertia of the metal hammer replacement.
I think that Yamaha is using a metal weight to emulate the behavior of the hammer, and I think they have made this hammer a little too heavy. This screws up the key rebound- try to play Chopin's Nocturne in C sharp minor (posthumous) and you'll see what I mean. The trills are completely out of control due to the inertia of those metal heads. I think the Kawai's RM3 Grand II action suffers from the same problem. The PHA III action of Roland LX-15 has a smaller metal part (from the action models I see in the shop) and seems to be better of the three makes- at least the same trills play better.
In conclusion I think that Yamaha hasn't nailed it this time at least with the action which is rather disappointing. So if you're looking for something to play like a real acoustic this is going to disappoint - the technology just doesn't seem to be there - yet.