Does anyone have experience whether the switch from an Xbox One X to a Series X is worthwhile?
Yes, if you want to spend the money and yes, if you have a decent TV or monitor to see the graphical advantages.
The optimized games mostly run in 4k at 60 FPS. There are also all sorts of details (ray tracing) that make the games more attractive. Even unoptimized games without frame lock now run with more FPS, such as Battlefield 5, now feels super smooth. Older games that did not have it before get the option to activate Auto HDR via the console, i.e. To display a kind of fake HDR, which looks really good depending on the game.
A few titles even allow 120 FPS at the moment, although the resolution or graphics are compromised.
In addition, they load incredibly quickly thanks to the SSD, the console is whisper-quiet and quick resume is an absolute killer feature.