I had my D2 for about a week when I realized it wasn't for
me so I sent it back to exchange for the i7. My i7 came last night - MAJOR kudos to adorama.com for getting it to me so fast. The i7 is much smaller, and suits my needs perfectly. It doesn't have the expandable memory slot, but thats a sacrifice Im willing to make to have an all-in-one device I can use anywhere.
Well what can I say ...... the i7 is
exactly what I've been looking for. The sound, to me, is wamer and a lot more "fun" compared to the D2. People online have said that and I thought they were just trying to come off as fancy talkers but I have to agree.
The swing touch interface is a breeze to use, no complaints at all. The unit takes about 7 or 8 seconds to power on, I just upgraded the firmware to 1.17 from 1.16 but that's the only complaint (and that is small). I would prefer to NOT show album art, but unfortunately all of my files have it and Im too lazy to dig through and remove them.
16GB is plenty of space for me, most of my files are 192kbps anyways so I dont have lots of large FLAC or OGG files to worry about. Very, very happy with this purchase.

x 100
I felt the D2 was delicate in regards I was worried about scuffing it up just sitting it in my car's cup holder while listening on the road. And, trying to navigate that silly touch screen while driving was a nightmare. Cowon's interface isn't the most intuitive out there, and this just made it MORE difficult.
If all you do is listen at your desk, or lounging around, than the D2 is a good choice. I just knew for me the touch screen was a pain in the ass and I would constantly be paranoid of damaging it from everyday use. Good luck, if you have any questions please feel free to ask.