I might as well throw in my 2 cents here because I just bought the S9 and my impressions are fresh. Unfortunately, I've never owned the D2 so I can't offer a direct comparison, but I can comment generally on the S9 sound. I got the S9 two weeks ago hoping to get a significant sound improvement over my iPod 5.5g. What a disappointment. To my absolute surprise, I think I'm going to return it because I prefer the iPod! Perhaps my ears have just gotten used to crappy sound, I don't know.
What I can say about the S9 is that it does a beautiful job making the music sound "live." It is super-detailed, very forward and in your face. But what I personally find lacking is the soundstage. I've done A-B with my iPod and the S9 using virtually every EQ and I still can't get it to sound as wide or airy. Likewise, the soundstage sounds "flatter" to me on the S9, whereas with the iPod it seems like there's more depth, like I can hear when an instrument is farther away from the listener in virtual space. I had no idea a DAP could have such a profound effect on the soundstage! I'm using SE530s by the way.
I keep thinking I must be crazy, but I can't argue with my ears? I listen to classical music, so the soundstage thing is a deal breaker for me. I might prefer the S9 for rock, but I'm not sure.
To review a few other things quickly...
PROS:
Battery life is very good. I love the ability to record the radio.The OLED screen is absolutely gorgeous and the ability to play xVid is super convenient. The player is incredibly light, something many reviews counted as a negative, saying it made the player feel cheap. I think that's ridiculous - since when is being light a negative in the tech world? On the contrary, it's nice to not feel like I have a brick in my pocket!
CONS:
Unfortunately, the video player is somewhat buggy and freezes up on me sometimes. The touch screen is... touchy... it's definitely not snappy like the Touch or iPhone, and more often than not I'm wishing I could just use tactile buttons and be done with it. It's just really clumsy and certainly not helped by the UI, which is so poorly designed and requires so many steps to perform many options, I've spent more time feeling frustrated than enjoying the experience.
So, for me, all in all a mixed bag. I wish I could combine the detail and power of the S9 sound with the soundstage of my iPod and I would be in heaven. But back on planet Earth, the S9 cost me $250 and I'm going to return it for something that doesn't raise my blood pressure so much.
Oh, and have mercy... don't tar-and-feather me for preferring the iPod! Have I lost my mind completely?
