When my 5+ yrs-old iPad Pro 3rd gen gave up the ghost I tried the S9 Ultra as I am an comic artist and a 25yr Wacom user on the desktop, and the pressure curve differences between Wacom tech and the Pencil have always made it difficult to get my lines just so when switching between them. A friend has the S9 Ultra and uses Clip Studio, which is pretty much identical on every platform, as I do. He loves it so I said I'd have a go, despite being fully in the Apple ecosystem.
So I picked one up, traded in the Pro, and took advantage of the free Galaxy Watch 4 and free Buds2 Pro that came bundled. After the trade-in, and immediately selling the Watch and Buds on eBay, I think I spent £680.
PROS: The drawing experience is better if you're a Cintiq user. It's as good as I have used on a tablet. Handwriting recognition had some useful features, like convert to type, that I liked. There's a general sense with Samsung that they are trying to out-innovate Apple, and a lot of the features are undercooked, but the novelty is enjoyable and feels like old times in computing. Beautiful OLED screen, great sound etc. The M4 iPads weren't out when I got it so I couldn't do a side by side. I felt like the battery life was excellent, but then I was coming from an iPad that would hardly hold a charge, so YMMV.
CONS: If you're deep in the Apple ecosystem, you are now effectively operating with one hand tied behind your back. We all complain about Apple system settings; well, good luck with Android settings, where almost nothing is where you hope it would be. The little rubber nib on the S-Pen is very fragile - I tried putting a Paperlike screen protector on and it damn near tore the nib off. The bad news: you can't buy replacement nibs with the rubber tip. You have to buy a new pen. No saving directly to the cloud via a file dialogue as far as I could work out, in any of the art apps I use. The screen is huge, but as an artist, widescreen in smaller sizes is useless. Too tall in portrait, wasted space in landscape, and anything smaller than a 14" screen is narrower than a sheet of A4 paper. Unwieldy to use in the lap. And so on.
Three weeks later I bought the 13" M2 Air. Unequivocally a worse screen and a little less pleasant for me to draw on, but it's still a better day-to-day art and light-use device (I will never be a tablet-as-laptop replacement person). I don't know what question the S9 Ultra answers other than, I'm a Samsung fan and I want a tablet that works with all my other Samsung stuff. In that category, it is excellent. Otherwise, as others say, it's a great media consumption device, but at the price, what is the point?