The Positives:
Sound quality is def above the average mp3 player esp above most ipods, esp with a decent set of headphones(included are not so good)
Incredible Battery Life (aprox 64hrs+ for music)-Major Selling point!
Sharp colourful display(new OLED touchscreen display)
Touchscreen is quite responsive (capacitive) but not quite as easy to use as ipod
Drag and drop onto cowon as an external drive on pc so no need to mess about with unresponsive provided software(better than encrypting like ipod/sony)
Memory Expandable/Upgradable(Put in a micro sd for instant extra capacity.-ie add 16gb card to get a 32gb player and more in future)-Brillant
Wide range of video formats acceptable,eg divx(but not all and Not ipod mp4 video files!)
Supports flash but don't have clue how to do anything with that??-def nothing like an app store
Light and ok quality build for an mp3 player, display does smudge but its glass so cleans up easy
Actual physical buttons on side of player, which means you can use in your pocket, unlike other touchscreens
Digital radio and photo viewer as standard, plus recorder, from radio or inbuilt microphone, so good for long lectures/meetings
The Negatives(which lose a star)
Display, while exceptional + sharp indoors, is almost unwatchable in bright sunlight, and def. dimmer in comparasion to ipod on brightest settings
However over 10 hours video so better than most.
As said, does not support ipod/psp movie format (yet?)-Big let down for anyone with a sizable movie library.
No wifi, or internet browser if that matters to you, but is bluetooth.
interface is not great as sometimes hard to find way to what your looking for, but not too bad and you do get used to it.
Included software not very clever, but will convert other format movies to divx, but really widows media player is better.
screen is little small(3.2" when most videos are heading for 4" now)
No home button which is tricky for a touchscreen, but holding play button does the same
in built speaker is a litle quite on max volume, but still pretty good.
Build of device does seem a little plasticy and cheapish on the back, despite the metallic edge round the glass screen on the front,all metal be better
Instructions non existant and some options almost a mystery to figure out, with button images no help-(or fun if you enjoy experimenting?)
For same money could buy ipod touch with bigger brighter screen and still decent audio and battery life and wifi and web browser(Big Negative)
Conclusion.
Using this just as an mp3 player and occasional video player,this device is perfect really, as battery life is very decent compared to others and pretty perfect audio playback, for those with normal human hearing, and better than compared to ipods and sonys had before. As a video player its not quite as good as others,perhaps sharper than ipod touch but def not brighter-esp in daylight, however longer lasting so maybe up to you to chose which you prefer.Nice if bit bigger. The other features are little sparse as photo viewer is standard for most now, and even nano has inbuilt video recorder, but as yet cant figure how to get games on it and as with touch dont generally like prodding a screen or balancing it to play games on, so not really bothered. Anyway, audio is the focus on this so it excels there and too much other stuff might distract.The ultimate and interesting point is the upgradable memory part, as in 2 years the micro sd cards could have doubled or tripled which ultimatly future proofs this high quality player, at least in capacity terms. Can't see major audio developers like apple/sony following this(maybe sony if their smart)Could be improved in a few ways.Perhaps a swappable battery might help but ok. And if drag and drop is too easy, maybe a better software from cowon and def an all metal body as feels rather cheap and light.
So Summary, light, bright, long lasting upgradable memory capacity with great sound quality. Other little niggles can be mostly ignored, in my opinion.
-Update after 2 months use, only to add that audio still impresses and a 32gb sdhc card is now available, and contary to my earlier comment, found supplied software ok once you get used to weird interface and has benefit that will actually let you add apple format mp4 videos,(so ipod movies you have not wasted!)-and also converts video files if not suitable- so big plus. Only negative now is that the white back of mine looks very grubby after a few weeks in pocket, so would probably recommend the black one.Still highly recommended-hope that helps.