Pixel Preview is broken on different zoom levels
In 24.4, on web-based profile, Pixel Preview mode would blur the result for a pixel-perfect image, when Zoom In or Zoom Out commands are used.
When you disable and enable the mode back, the rasterization gets restored.
Please see the attached image.
Also notice how a canvas shifts when you switch modes.
Konstantin Homatyano commented
I have this issue too. The pixel-grid snapped image looks crisp the moment you turn the Pixel Preview on (Crisp.png). But once you zoom in or zoom out, it becomes a pixel mess (Blurry.png).
The reason for that it seems is the zoom factor. For pixel preview to be crisp, the zoom needs to have some weird fractional value. But the commands zoom in/zoom out jump between nice rounded zoom levels thus turning the pixel preview into an unusable mess.