When you activate it you agree that your voice input is sent to Apple. As far as I understand this project runs fully locally. Up to you to decide for whatever suits your needs best.

Nothing comes close to LLM transcription though. I just tried this. I said "globe key dictation, does this work?". Here's the transcription, verbatim:

"Fucking dictation, does this work"

yup, this is how I 'type'