We have pretty severe issues with text rendering performance also.
Both Mac 12.5.1 and Win10 have shown the problem with juce 8.
Here’s a simple demo project showing the difference.
Use mouse wheel to zoom the view in and out.
Switch your juce global paths between j6/7 and j8 and it will be immediately obvious.
Also, note this other thread: JUCE 8 Text rendering performance - #2 by cxhawk
textRenderDemo 2.zip (19.8 KB)