Just saw this. Not sure if you're still considering what to get but I thought I'd add my $0.02 from personal experience.
I have owned an NV10S since June of last year and play it every day. I exclusively use VSTs and have accumulated a huge selection of (approximately 200) VST licenses, starting about 10 years ago. This includes full licenses for all of the VSL pianos. I use Cantabile Performer and can view and select all my instruments and save all my custom settings.
I typically use headphones for classical practice, connected to my Motu 4 audio interface, but also blend the internal sound with a pair of Neumann 310a monitors and a Yamaha HS8s sub.
My feeling is that the NV10S is a superb, if somewhat expensive MIDI controller. I don't know what they sell for today, but I bought mine new on sale in 2023 for $10,000. I probably have nearly that amount of money invested in software licenses, so I certainly could have had a decent upright acoustic (no room for a grand at any price), but I really wanted to be able to have the versatility of MIDI and software instruments provided I could have an acoustic grand action. I've played a variety of acoustic grands and uprights over the years and the NV10S is very much a true acoustic action.
It's funny that I originally played the NV10 back in 2021 at a showroom and didn't care for it, both in action which I found sluggish and the sound which I found unrealistic. At the same time I tried the Yamaha N3 and had decided I would wait for an upgrade to the N2 When the sale came up last year, I was tired of waiting for an N2 upgrade and somewhat impulsively bought the NV10S. From the first time I played it in my livingroom I loved everything about it, except for the internal non-headphone sound which I still found lacking. I already had Yamaha HS7s from my old MIDI controller but I found them a bit piercing and decided to upgrade to the Neumans based on some research and that did the trick. Headphone sound is superb. I initially had some sensitivity issues with the damper pedal which I was able to resolve via a virtual technician software setting and some creaking which required lubrication of the damper pedal rod.
BTW- a big advantage of the Avantgrands is the internal audio interface. I have a P515 in my basement office and the MIDI hookup is quite a bit more flexible (though that keyboard is a toy compared to the NV10S). With the NV10S, I have to use a Roland MIDI to USB cable and then loop the sound back to the NV10S line-in to have it go through the piano's internal sound system. All this is unnecssary with Yamaha's internal audio interface. The Kawai approach ends up working ok but it's a of a pain to set up and adjust.
My NV10S is a joy to play. I live in a rural area and I have concerns with getting service for electronic issues, but that's a risk I was willing to take. Good luck and good hunting!