I worked in that field for 8 years for a somewhat known plugin editor. We used JUCE a lot at the beginning, but ended up slowly moving to an OpenGL-backed rende

I worked in that field for 8 years for a somewhat known plugin editor. We used JUCE a lot at the beginning, but ended up slowly moving to an OpenGL-backed renderer for performance-critical parts (eg: VU meters and other audio-to-UI feedback), and JUCE for the rest of UI scaffolding (layout, controls, menus etc). Same thing went for the other parts of a plugin architecture: we wrote our own VST/AU/AAX interfaces with the DAW to overcome some of the issues we encountered with JUCE. After I left the company, my former teammates rewrote the whole UI framework to a pure OpenGL implementation. I'm not sure if there's even a drop of JUCE in the codebase anymore. Note: this was before the PACE acquisition (though we had good contacts with the PACE team, their founders being brilliant engineers). So my advice to people starting in this field: use whatever is available now, JUCE is a treasure trove for beginners, then slowly optimise where needed.