Only the mini is meant for pure transcription. And with the tests I just did on their API, comparing to Whisper large, they are around three times faster, more

Only the mini is meant for pure transcription. And with the tests I just did on their API, comparing to Whisper large, they are around three times faster, more accurate and cheaper. 24B is, as sibling comment says, an omni model, it can also do function calling.