The NW-E50 is testament to "less is more" as this player is only a little larger than a matchbox. With a long battery life and features traditionally found on larger, more expensive players, the NW-E50 is a packed little powerhouse of MP3 playing power.
It is definitely the right size for people on the move, as it could easily be tucked into a shirt pocket or arm band. The 2-colour backlit screen is small but serviceable and it is easy to read and can display the group or album, as well as the song title. There is a "jog dial" on the corner of the unit that can be used to jog and shuttle between tracks and this takes some getting used. However, once you get the hang of it, you will love the control it gives out. Instead of searching for tiny buttons (on an equally tiny button) the jog dial brings the most commonly used functionality to your fingertips.
The NW-E50 has 128MB of flash memory, which can hold up to 6 CDs of music using the ATRAC3plus format, (which most users will either love or hate). You can also play MP3 files, but note that 128MB will hold a lot fewer MP3 files.
The unit comes with a USB cable for transferring music across, along with Sony's SonicStage software, of which I am not a great fan but it does what it needs to do. It can rip CD tracks to ATRAC3plus format quickly and has a simple user interface, so it shouldn't be too difficult to pick up.
The user manual touts that you can get 70 hours of continuous playback on a single AAA battery and while I didn't stay up for 70 hours straight to find out, I was amazed at the battery life, as over two days of near continuous play, the sound was still clear and crisp.
My one complaint is that the Sonic Stage software did not install correctly on my computer in the first instance and I had to remove it and re-install it. On the first install, it would crash the program whenever you dragged a sound file from the computer to the player. This can be frustrating for first-time users, but you will need their software installed to make the most of the player.
Still, even with software problems, it is a solid performer and packs a lot of features for its size.