We currently use what we believe is the best transcription software in the business, Google.
Our current setup, is to send your file to them and it usually takes about 1/2 the time of the duration of the audio/video to process. If it is taking much longer, please contact support.
Once the file is retrieved, it should be anywhere from 70-95% perfect depending on audio quality, accents, and other factors out of our control.
We have the handy option of being able to edit your captions! To see how to do this, check out this article: How To Edit Captions