There is a guy at synthogy (look there) he made a rachmaninov concerto and there is a interview at synthogy. He said he used his old and "beloved" Yamaha masterkeyboard for this, I dont know the type, maybe kx8.

Hugh sung who made a lot of demos for pianotek seems to prefer the Roland RD700SX.

Others that I have read about or seen use old Kurzweil controllers that probably have a Fatar action inside.

I think if somebody already is a pro-level pianist and has the ability to play on very different acoustics, he will not be too picky about the keyboard as long as it is reliable and compatible, as long as it has reasonable velocity characteristic and response and does the job.

For non classical playing they also use nonweigthed or halfweighted keyboards. Of course on stage the stars will always use a real black polished grand piano, because anything else doesnt have this show effect ;-)

If they are nonclassical stars (jazz or pop) then they are also under advertisement contract and preferrably use what they get from their sponsor in public performances... ;-)

I think they use everything that fits to the job.
Now if classical style is the goal then for example the old AWA grand pro from Kawai and a lot of older Yamahas and other brands would be the wrong choice. Say you have to play a repetition or an ornament fast but very soft.
It is simply impossible to do this, when the key must be almost totally
released. That has nothing to do with skills. It is impossible for physical and mechanical reasons, because it is impossible to move over a long keytravel distance fast and at the same time maintaining a slow attack velocity... Most older keyboards have this problem.

And if a real grand action is combined with a poorly constructed piano bar this would be impossible also....

"...Of course on stage the stars will always use a real black polished grand piano, because anything else doesnt have this show effect ;-)..."

Liberace. Elton.

The link to Liberace's museum of pianos is astonishing jaw-dropping.

Where did you get your stand for your MP8II?

I am in the market for one.

There are companies that sell stage-prop piano shells. These are hollow, fake piano cases that have a place where you can put a digital keyboard inside. The idea is that you get the look of a "real piano" but you get to play the DP. I don't know the number of performers who use these but it's enough to keep a small cottage industry in business. So you are right about the show effect. There is no other possible purpose to something like that.

The other thing, when you ask what do "most" performers use. Well, "most" pros are poor and they use what they can afford. It's only the very few stars and us amateurs (with day jobs) who can have what we want.

"Where did you get your stand for your MP8II?"

The Kawai dealer who sold me the DP. I've seen similar four-legged models at GC, Sweetwater. Around 80 bucks.