Looking for an mp3 player that is good at recording is like looking for a plyers that works good as a hammer. If you need to hammer, then get a hammer. If you need a plyers then get one. If you need both, then get both.
There are many reviews on review sites that keep repeating how bad all mp3 players are at recording. There are not reviews about how the more expensive stereo recorders work as music players. This is something I am curious about. For example the Olympus DM420 looks very interesting as a compact stereo recorder, however no reviews mention how well it works as a music player. It isn’t just sound quality, but ease of use and features.
Imo the most important feature of a recorder is a microphone jack, so if the internal mic doesn’t work well enough, one can choose an external one. I have not bought a digital recorder yet, but have been considering the Olympus VN6200 PC, and DM420. I tried some sample recordings on my Fuze and Clip+. The recordings were not so bad if the player is within 2 or 3 feet of the speaker, such as a Clip+ clipped to the speaker’s shirt. From further away, the recordings on the Fuze and Clip+ are too low in volume, and have too much background noise.