Tried it on Windows on a powerful workstation. Felt sluggish. The framerate seems to be capped as 60Hz. My monitor is running at 240Hz. Removing the framerate limit could help.
Does it bother you when you see flourescent lighting that's connected to 50/60 Hz mains power and you just see violent flashing?
(edit: This isn't snark, I can't see changes that fast, but I know what they look like slowed down and that other people may be different to me.)
It's actually not even 60. The FPS target is configurable in the settings and for some reason the default is 57.
To all other comments in this thread.
So many "hackers" apparently did not hear about adaptive refresh. There is no need to update a static image every 240fps. You only need to increase the refresh rate for animations like scrolling, like in... everywhere??? Android, macOS, Chromium, Qt, and GTK(?) do this.
This is the exact opposite of what I want, actually: imgui keeps promising an official mode that doesn't totally melt the machine from running at peak refresh rate the entire time (since it was developed for games, not normal desktop apps), but it never materialises, and the hacks we all implement ourselves stop working as they update the code etc.
Everyone seems to want 9234567345863489634589 fps, when that's IMO completely absurd for a normal desktop app, e.g. editor! What you actually want is low latency, not constant massive bandwidth and power usage. If all your normal desktop apps constantly ran at uncapped FPS, your computer would scream and laptops wouldn't last 5 minutes on battery.