If you have older systems, I'd especially say wait since usually Microsoft tests older hardware last and not first. If you have the latest hardware like Zen2/3 CPU or 10th-11th gen Intel Core CPUs, you should be okay. For the most part.
Another good practice is to make sure your GPU drives are on the latest update, this is generally important since Intel, AMD and Nvidia do make some tweaks to improve integration with the latest Windows 10 builds.
I installed 21H1 on my Ryzen 5 3600 rig, and its butter smooth. No bugs whatsoever, the only bug I had was a small issue where the start menu wouldn't pop up, but it rectified itself pretty quickly, plus I restarted to make sure everything was fine, and yup that's the only bug I've gotten.
I did get that issue too where windows update said to reboot to update, just igore it, if you leave the system as be, it'll fix itself. I've always had small bugs like this on major windows 10 updates and it won't interfere at all with your system usage.
With this update,I've noticed animation and speed improvements with Windows in general, even scrolling is smoother and I'm not getting weird hiccups with the settings app or the search bar anymore.