re: "Seriously the stage piano should win the day on piano" -- neither board is what I would call a stage piano, I had to think about which one you were referring to in that sentence.

The only new tech in the YC is the organ. I would expect the more capable, more expensive Montage to meet or beat it in every other sound. To me, the YC is an organ, with a selection of auxiliary sounds derived from the Montage (possibly lesser, as the YC lacks some of the sound processing capabilities of the Montage).

As for whether the YC piano is the same or has lesser velocity qualities compared to the Montage, you might get a better idea about that by running MIDI cables between them, and see what it sounds/feels like if you play each one's piano sound from the other's keys, and compare that it how those keys trigger those board's own piano sounds. Make sure you're comparing the same sounds, though. It may be, for example, that the YC Montage-derived pianos are strictly single-part pianos, the YC may not internally support the single-sound multi-part architecture, in which case I would expect there to be pianos on the YC that don't have all the velocity differentiation that some of the pianos on the Montage do.

re: "Montage and Genos. Something should clearly dominate on the YC above them both besides the organ feature. My Montage 6 costs less than my YC of course it was purchased used."

You can't compare new price to used prices. The YC is obviously built to sell for far less than the Montage or Genos. That is one place it clearly dominates, besides organ.

re: "Yamaha needs to fix this quickly IMO and make the YC have the edge for stage work." - Not only is it more portable (as you mentioned) and also far cheaper (new), it also has a much more direct way of working, a dedicated-knobiness which some people prefer. That also impacts the price. The CP73 and MODX8 cost the same, despite the former being essentially a sonic subset of the latter, the trade-off largely being one of preferring a more direct, knobby way of working with the sounds.

Yamaha advertises this YC as a "Stage Keyboard" whereas the Montage is a synthesizer.

A synthesizer should not have more advanced pianos and key sounds than a stage keyboard that was released 4 years after the synthesizer.

The forte of a stage board are pianos and keys & now with organ onboard. I'm pointing out that this doesn't really make sense specifically from a voice quality aspect.

I like them both, Montage dominates the market I think and the YC is a fantastic new creation.

I'm not sure I'll keep them both since Montage can do organs & the YC doesn't sound any better in any other way.

It is all about the sound quality but yes, each board has different purposes for other users.

I also think the FSX action is dominant over the YC quirkiness & lack of smooth or consistent key pressure. Why step backwards here? Maybe that's how organs are but I'm not sure.

A "stage keyboard" and a "stage piano" are not the same thing, that's why your reference to "stage piano" threw me. No hammer action? Only 61 keys? An interface that emphasizes non-piano sounds? Too many strikes against calling it a stage piano, in my book.

If the ONLY thing about the YC that is prompting you to consider keeping it is its better organ, and that doesn't seem worth the price to you, you could consider adding any of a number of organ modules to your Montage, or even an iPad running something like B-3X. The Montage has great functionality for driving external MIDI devices,

True I guess a stage keyboard could be anything with keys that can fit on a stage.

I do lump then together with the exception that a piano can be considerably larger.

I think it wants to be a "Swiss Army Knife" of keyboards. I don't play live anywhere so I'll eventually sell it.

I only wish I knew what Yamaha's intentions were, whether it will be considerably expanded such as with new organs and content all around.

Since it doesn't do much else within its design confines, expanding the content it is the only way up but the question is, how far will they take it &/or how far can the board actually go?

I think one should always buy a board for what it does today, not for what you hope it may be able to do tomorrow. That's what I believe even if a manufacturer says they intend to come out with some major upgrades, but even more so when they have said no such thing!

I've pre-purchased most every Tyros/Genos line and then Montage & YC when I heard about it. I pre-ordered the infamous EX5 and curse those dreaded processor overload messages.

My MO is to try all Yamaha gear out of the gate. I've only kept one Yamaha board which was my CP1. Might be buried with it. Funny Yamaha completely abandoned that unit but still make it. One OS update in a hundred years I think. I guess with that technology nothing could be added to it. Some voices programs packs would have been nice.

I did sell my Montage 8 (too big and key action wasn't enjoyable) because the Montage ESX was supposed to be released, well, according to Yamaha's track record over the last million years. I do not like surprises as you can tell.

I wanted an organ my whole life but resisted the Nord, Hammon etc. forever. Once I saw Yamaha made one I bought it.

With 9 dependents and a COVID19 job loss I never actually own anything, everything is rented forever for my entire life. .

I'm only really interested in the technology and as soon as it bores me I sell it.

If you can pick up an excellent condition Montage 6 for less than a YC, I'd probably do it. I even saw someone sold (gave away) a Montage 7 in the Ebay sales history for about what I paid for my 6 at 1750. I was sick I missed out on that one.

No, the YC isn't worth anywhere near what I paid. It was really cool in the beginning but 500 overpriced and the Montage 6 kills it still even for stage work.

The YC micro-screen is 1980s. Seriously, significant older people play these boards and I doubt many of them can read the screen.

YC sounds great and is fun, great interface for what it does but in comparison to a used Montage 6 I'd stick with the Montage 6 or wait for a used one.