for line in you can plug it into a CD player and directly record music being played on the CD player. so if your friend has a song you want on his cd player just plug it in and hit record on your mp3 player, which gives you cd/mp3 quality music.
i have a creative zen micro so im assuming its the same radio unit. the FM radio is pretty good but it gets a pretty weak transmission. so you will probably get less radio stations.
-also if its the same radio unit it uses the headhpone cord for radio antenae so lying down is more fuzzy(thought id add that cuz i duno how u plan on using this.)
N200 seems more popular and my friend is very happy with his(he got a black 1)
I really don't know a difference between the two..except maybe the small change in prices....But what I'm wondering is how the FM-Radio recording is on both? And how the Line-In recording works...Any insight on which is better between the two would be extremely great..thanks.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic