I used it a lot in my AI client before I finally got around to hacking a Deepgram API server into Handy: It sucks enough to give me a headache worrying about its unreliability in every given transcription.

They supposedly improved it on later Apple Intelligence enabled devices, but I don’t have one.

apple's is 5x faster than `large-v3-turbo` with whisper.cpp and in my test had somewhat worse performance, so it's a tradeoff

I suspect Apple's strengths are in multi-language support.

I use their on-device translation in my apps. Works pretty well. ChatGPT's context-aware translation is better, but it's not on-device.