From personal experience we can get pretty good results on our workflow from sphinx - but the amount of time it took to get those results was massive, and sprea

From personal experience we can get pretty good results on our workflow from sphinx - but the amount of time it took to get those results was massive, and spread over years. It's probably worth it for most organizations to skip that and go for a vendor. Results from Amazon are an unknown right now, but the other vendors vary a good bit and are focused on particular kinds of audio (kinds vary by: the number of speakers, the duration of the audio, the vocabulary, language).