Yeah, no secret inside info, the the "N(something)X" is the current gen for Yamaha. Considering it took 10 years to get from "N(something)" to "N(something)X" I imagine you're safe from anything new coming out tomorrow. The most likely "I wish I'd waited" regret scenario is that prices will drop, especially with the Kawai competition.
Makes sense, though it seems the NV5 has a bit higher price point. Think Iâ€™ll wait for the local store to get the Kawai in so I can try that before deciding.
I think you're making a very wise decision. Yes, I know there are those people who say that if you keep waiting for the next best thing you'll put off buying forever, but in this case you're comparing two models that are competing directly against one another. I don't know how long you'll keep your next piano, perhaps about eight years of so, but it will certainly be long enough that being patient now is a big virtue.
I'm writing from the USA, and using exchange rate values, along with expected dealer discounts, I'm guessing that the NV5 will cost about $500 USD more than the NU1X, which I can get for $6,000 including all taxes and shipping. To me it would seem that the numerous voices and features of the NV5, as compared to the spartan NU1X, would justify the increased price. Except that there's so much more to consider. Will the acoustic upright feel of the NV5 be as wonderful to play as the NU1X? How about the damper pedal? The sampled/modelled tone of the Kawai compared to Yamaha? The headphone tones? And who knows what else?
What all this means is that you're going to have to do a lot of testing, and you certainly can't settle for playing each instrument just once. And when you do get your new baby home, at some point you'll wonder if you made the right decision. I can guarantee that will happen more surely than I can guarantee that the sun will rise in the east.
At any rate, best of luck in your buying decision.