Just to further clear up, as long as you receive a legitimate D2, it will come with a manufacturer's warranty, so whomever you bought it from will no longer matter.
I got a Zen 4gb a while ago, didn't like that, sold it and got my D2 in yesterday. Definitely a big difference, the Zen appeared to me to have virtually no bass, the treble was okay on it though and it had a warmer less articulate sig which would make it quite good for pop I presume. It also had a completely useless SQ imo, it had a base boost function but that helped little.
In comparison the D2 makes my phones sound highly articulate, almost overly to the point that I can almost see what people mean when they say they're getting robotic voices (although voices sound fine to me ...). Bass comparatively is also very good but is a bit too precise/transient for my liking. In comparison my H320 still hits harder and has a nice but not exaggerated bass boom.
Also, I've heard people say the D2 cuts soundstage, but I haven't really noticed any of that so far.
Video quality looks good, I can't really compare it to any degree with the Zen because I didn't them both on hand at any one time, but from memory the Zen was marginally better, but certainly nothing significant.
Oh and yeah, touch screens are annoying.
Also, forgot to mention the screen on the D2 is quite hard to see in direct light compared to other DAPs I've tried. It may actually be the protective layer I've got on it, but still it's annoying.
