First time running CEMU, and although shader cache stuttering was everywhere, being able to run Super Mario 3D World on my machine at mostly 60FPS is like magic to me.
Also, IIRC, OpenGL has been historically more accurate in emulators like Dolphin, in which some games had accuracy issues with the D3D APIs. Sure OpenGL isn't the best performing API, but it's usually one of the safest.