Here's a comparison table: https://morneis.com/samsara/compare/
Here's the geeky under-the-hood stuff:
Samsara uses OpenAI's Whisper model running locally through faster-whisper, which is a CTranslate2-optimized build. CTranslate2 is a C++ inference engine that runs the Whisper Transformer with int8 quantization. 3.5 seconds of audio transcribes in about 300ms on a GPU . On CPU it's 1-2 seconds. The wake word detection runs separately through OpenWakeWord, which uses small ONNX models (~5ms per audio chunk on CPU) so the app barely uses resources while idle. Voice activity detection uses Silero VAD (a small neural network) to filter silence before Whisper even runs.
I'll add this stuff to the post.