I have several my own little success stories:

- For polishing Whisper speech to text output, so I can dictate things to my computer and get coherent sentences, or for shaping the dictation to specific format eg. "generate ffmpeg to convert mp4 video to flac with fade in and out, input file is myvideo.mp4 output is myaudio flac with pascal case" -> Whisper -> "generate ff mpeg to convert mp4 video to flak with fade in and out input file is my video mp4 output is my audio flak with pascal case" -> Local LLM -> "ffmpeg ..."

- Doing classification / selection type of work eg. classifying business leads based on the profile

Basically the win for local llm is that the running cost (in my case, second hand M1 Ultra) is so low, I can run large quantity of calls that don't need frontier models.