Pallas I haven’t read every post in this thread. But here are some additional thoughts and questions (and you may have answered some of the questions already, I just didn’t see them when I scanned through the posts).
If you’ve got the financial resources, the space, and it won’t cause problems with your family, there’s really no need to justify the purchase. Buy the piano you want.
That said, you got your upright not very long ago. What is it that you feel is missing in it? I saw ‘dynamic range.’ I also see that you have looked at grands that you like, so there is presumably something that you’re getting from those grands that you’re not getting from your upright. I also see that some of this may have been brought on by going to a Jeremy Denk concert. I think that may be a little dangerous— there are a lot of reasons he can make a piano sound fantastic that have much more to do with him than the piano. I’m a fairly advanced amateur, and while I can access a fair amount of dynamic range, my teacher (who overlapped with Denk at Oberlin and plays very well but is not Jeremy Denk-level) can get both a lot more and a lot less out of a piano than I can. It’s also one of those things that I have continued to make progress on. But what I’m wondering is how much of your dissatisfaction with how the YUS5 is performing — and what you’d like to see it do— may be colored by things that a different piano won’t necessarily make better.
My next question relates to your current instrument. Are you sure the YUS5 is performing at its best/has been optimized for you? You have what is considered to be a pretty high end upright, and I think that a YUS5 should have a very good dynamic range. It won’t compare with a Bosendorfer 280 VC, but from what I’ve gleaned, that’s not really in the cards, for both budget and space considerations, and personally, for home use, a full concert grand feels overkill IMO. Plenty would say that about my 7 foot piano, as well.
Back to your YUS5. I would think about bringing in a really good tech to regulate and voice it. Try to describe what you want the piano to sound like. This was an expensive piano, and I think it should respond well to this kind of treatment. You could also consider moving it around the room and/or adjusting some of the room treatments, to see if this helps.
Anyways, those are just some questions/thoughts. If you really, really want a grand piano, for whatever reason, and you’ve got the resources, then there’s no reason not to pursue it.
