Parallels is quite good - I can watch 4K YouTube videos at 60fps with no noticeable frame drops on an M1 Pro, and general desktop animations, etc. are fine. That said, I do occasionally get rendering glitches, usually in Firefox where a small rectangular portion of the screen will briefly flash black while scrolling quickly through a page.

The biggest quality of life issue for me personally is the trackpad. Although support for gestures and so on has gotten quite decent in Linux land, Parallels only sends the VM scroll wheel events, so there's no way to have smooth scrolling and swipe gestures inside the VM, so it feels much worse than native macOS or Asahi Linux running on the bare metal.