I used Cura 4.1.0 for a while now and everything was fine. Later I installed 4.2.1 and 4.3.0. These versions are barely usable. I now have all these three versions on ONE Computer. Cura 4.1.0 is still fast. The younger versions are not.
Startup, slicing, everything is slower. Moving the viewport in preview is a real pain.
Markus