Drop in a WAV and get MIDI you can edit. Lossless audio gives the AI the cleanest signal to work with, so note detection and timing come out tight — and you get the notation and MusicXML alongside the MIDI.
WAV keeps the full audio detail that MP3 compression throws away, so the AI has a cleaner signal for pitch and onset detection. On careful recordings that usually means tighter timing and fewer wrong notes in the resulting MIDI.