Ok, I just performed a carefully controlled study using the most advanced and recently calibrated scientific equipment
I think it would work well for your intended use. I did a few test recordings at about 14" and 30" with a normal speaking voice. The recording was very clear and strong, although the mic is
very sensitive. If you move the player around while recording you will get a contact noise like as if you were tapping a regular microphone.
It even picks up whispers, be careful what you say
Only negatives are the user interface which has a different menu for recording vs playback. And if you were in an area with a lot of background noise, I'm not sure if you could adjust the mic sensitivity to tune this out.
As an MP3 player I've been using it for a month to workout w/the Bose earbud headphones and the sound quality is excellent. For the money it's a nice little unit.
-spence