Bought a Stage 3

[Steinway]

First of all: does your wife need an interim solution, or a piano that she will be playing for years to come? In the latter case, and considering that you're selling a Steinway/Boston (if it's an upright, you should be able to get back at least 10000€, no less than 20-25000€ if it's a grand piano), I'd buy a much better instrument.

That is, if you only need a good digital piano and nothing else, you shouldn't buy a Nord. Nord's digital pianos library is pretty good and the Grand's action's excellent, but we shouldn't be partial: many of those sampled pianos are old, dating back to 2011 or even earlier. Of course, Nord offers many great pianos, especially the XL versions (that is, the most heavy ones) released after 2015. Those pianos can definitely compete with the Korg Kronos' or the Motif's, despite being much smaller in size: some of them, like the Grand White and the Velvet, are arguably the best piano sounds on the workstations market (you'll find a couple of blind test videos on YouTube crowning Nord as the king/queen).

But all this concerns workstations, that is keyboards that are designed to do much more than just acoustic pianos. If your wife doesn't play organs and EPs and isn't interested in any other sampled instruments (from strings to guitars), then Yamaha and Roland's digital pianos are probably the most sensible choice. You can get the same sound quality for much less than a Grand: take a look at the Roland LX series, a Yamaha CLP or any other digital piano in that price range.

That said, as I wrote above, if you're seeking the best digital piano on the market and have no budget limitations, you should buy a Yamaha Silent, which might be exactly what your wife needs, albeit it's much more expensive: but a used one (and honestly there's no reason not to buy a pre-owned piano) can you set you back less than 4000€ (e.g. a B1 Silent).

[cphollis]

The question of "who delivers the best acoustic piano samples" is subjective at best. The consensus winner would probably be one of the better software pianos. Which isn't what OP wants.

As far as hybrid acoustics, it's a different class of instrument entirely. You're buying a piece of furniture as well. Lots of good choices here, all are expensive. My Yamaha AG N3 is a wonderful digital instrument, plays like a real piano, looks great in the living room, etc. Sort like the Silent on steroids.

And not what the OP was looking for, as far as I could tell.

Having played both a NP4 with Nord Piano Monitors -- and a nice Yamaha AvantGrand N3 -- I can do a quick comparison. Both have great keybeds that satisfy, albeit different. Both are good enough that you can lose yourself and forget you're playing a digital instrument.

Not a ton of voice flexibility on the AG, but not a big deal, as most real pianos only have one setting

The AG is designed to fill a room much the way a real grand does. The NP4 with monitors creates an exceptionally detailed soundfield for the player, which drops off quickly as you step away. You can hear all the nuance and grit of the different pianos on the Nord setup. It's pretty close to listening on headphones. And all those different Nord piano samples have a ton of authentic character. You'd be surprised how sweet a tinkly upright can sound.

We also have to acknowledge that the different vendors have different approaches to acoustic piano samples. Most of the slab piano voices are processed to sound good on stage, sit well in a mix, etc. Fine, but ... you can't easily get down to the raw sample, if that's what you want.

By comparison, the Nord samples are great recordings of real instruments. I can't detect any significant processing after the fact, which is exactly what I want -- the authentic sound of a real piano. If I want reverb, compression, etc. I can easily add it.

Thankfully, there are a bunch of great choices out there depending on what you're looking for.

[Steinway]

Having read all your very helpful replies, and having listened to some more reviews, we are pleased we have returned the stage 3, we have not yet heard a keyboard through our yamaha hs8s we use on our computer, through a d to a converter, that we think sounds as good as a Nord Grand.
We do not want a heavy piece of furniture and not to spend over the 3200 (aprox) of the Nord Grand. We are investing in a QSC K10.2 (based on earlier recommendations on this forum), which we believe will be better than the Yamaha HS8 we are using.
I see that some of the digital pianos have around 200 watts of internal amp and that is something that worries me as a hifi enthusiast, knowing the extra control a bigger amp can have to reproduce the sound of a grand piano (especially bass notes down to 27.5 hz), even at lower sound levels. This may end up with me buying a 12.2 for the left hand.
My wife is going to try our old Roland HP302 again to satisfy herself to the sale of that one... I know which way I would go but it is now up to her to decide. Watch this space.

[Steinway]

We are investing in a QSC K10.2 (based on earlier recommendations on this forum), which we believe will be better than the Yamaha HS8 we are using.
I see that some of the digital pianos have around 200 watts of internal amp and that is something that worries me as a hifi enthusiast, knowing the extra control a bigger amp can have to reproduce the sound of a grand piano (especially bass notes down to 27.5 hz), even at lower sound levels. This may end up with me buying a 12.2 for the left hand.

Here are some thoughts, but I would defer to @cphollis as he is one of the best sources you will find for knowledge of amplification.

1. You will want two speakers for stereo reproduction.
2. The QSCs may be a bit of overkill for an apartment. They are super loud, and while they are OK to use as nearfield monitors (I did it for a while), they won't be as clear or enjoyable for the player as nearfield studio monitors would be.
3. If you are set on the QSCs, the 8.2s go deeper than one would think. The 10.2s may be an unnecessary increase in cost and size.
4. For a living environment, a pair of column PA speakers (Bose L1 Compact, Turbosound iNSPIRE iP500, etc.) will blend in better with the décor and provide a more refined sound.

[Steinway]

+1 for 1..3 of your points, ajstan! The QSCs have a fan built-in that you will hear softly if they are quite close to your ears. I like my K8.2s very much, but I'm not at ease with them in my small music room.

But contrary to you, ajstan, I'm not a big friend of those Bose L1s. Don't like their piano sound very much. I don't think they have a flat response curve.

Unfortunately, I don't have a good advice - if you don't want the Nord Monitors or other near field studio monitors.

[Rusty Mike]

As a longtime user of multiple generations of the K series speakers, I can also affirm they not the best suited for home use, even with a stereo pair. The 8’s would fare better then the 10’s, but I have always felt they sound much better from at least 3 meters away than half a meter away.

Those Yamahas never suited my fancy either (for what it’s worth). I recently purchased Presonus Eris monitors for my home studio, and am rather pleased with them. I have a pair Eris E3.5 for my office computer and the Eris 5’s for my music computer. I would recommend the E7 or E8 for the piano. They are lively, crisp and pretty neutral sounding.

[cphollis]

As above, there's a serious chance that a K.2 (or any PA unit in that class) will overpower the space you're in. The neighbors might like it, though. Great for gigging.

As far as amplification, you'll have to decide: fill your living space, or just create a great listening experience for the player. Near-field monitors do the latter very well. Filling the living space takes you down the road of home stereo systems, which can be pretty good.

One setup that worked surprisingly well when I tried it? Near field monitors (a-la-Nord or similar), and a hardwire to my home stereo system at modest fill volume. Bluetooth can work, but watch for latency.

[JayDee]

As expressed. K 10's IMHO would be overkill for home use, Yes I did have a pair. K 8's better, but the nearfields might be a better choice for you unless you intend to gig (or have a BIG space)

* Bear in mind a lot of the respondents are pro's with VERY discerning ears. You can certainly do better with a good budget than the HS 8's Even in their approximate price range ( + or - around $1000 usd pair) you could likely do better. I have a pair of HS 8's in my home studio and by my standards they are decent, if not the best.

[Steinway]

Following all your advice I have managed to cancel the K 10 and have thought about the home Hifi approach rather than stage sounds. I have remembered I have an active XTC system (retail around 5000) which is based on 2 5.5" seas units and a tweeter in a diapollito design, driven actively from a pre-power amp built by a speaker/amp designer. I am constructing a table for the nord with a built in side table for the amp. A speaker, on its own stand, either side. Hoping this may sort out the challenge. Otherwise no cash spent yet, so can decide next move after the testing. Should be good, and Nord Grand coming in a weeks time (I hope). Thanks again for all your advice.

[Steinway]

... I have remembered I have an active XTC system (retail around 5000) which is based on 2 5.5" seas units and a tweeter in a diapollito design, driven actively from a pre-power amp built by a speaker/amp designer....

One thing to keep in mind if not mentioned already, is that home stereo systems are designed for audio that has been processed/compressed to a great extent. Playing a raw instrument through a home stereo system (especially a keyboard with a broad, dynamic range) can significantly damage the speakers if you are not careful of the volume. The different models of Seas 5.5 drivers vary in output from about 70 watts long term to 150 watts long term, so playing at a moderate volume near-field should work well, but you'll need to be careful of cranking it up just the same. Good luck to you.