It's outstanding. The recording and playback voice quality are all outstanding quality, and the battery lasts for a very long time (many days of daily use). Compared with the previous version, Olympus has expanded the range of slow/fast-speed playback speeds, which is very good for language studies (previously it went up to 1.5-times speed, now up to 2-times speed).
The volume of the speaker is quite low, but it's not a problem for most people, as the volume on the ear-phones is fine. The function for defining and looping the playback of sections of the recording is very convenient for foreign language study.
The only things that would be nice to improve:
--There is no real "pause button", so listening sentence-by-sentence with pauses requires touching two buttons, stop then play, stop then play.. slightly inconvenient when listening to one sentence of foreign languages with pauses to digest the information.It's easier to just keep your finger/thumb on one button.
--When playing back looping-playback sections of the recording, pausing with the stop button de-selects the looping playback section, so it can't really be paused. However, since the batteries are very long-lived, I just temporarily pull the earphones out of my ear to rest when repeatedly playing back looped sections of foreign-language recordings.