Physically, it's slim and light and is about the same size as the K3. Ars Technica complained about gold colored buttons, but I don't see what the problem is. The color helps accent the buttons when you're looking at them but it's mild enough that it doesn't distract me from reading.
The general physical appearance is good. There's the keyboard, and above the KB are 5 buttons: home/back, a d-pad (the silver bar), and enter/option. There's a full size SD card slot on the right edge, USB port on the lower edge, and a power switch on the lower back (also the sleep button).
On second glance, the KB is fairly sophisticated so I'm going to have to spend more time playing with it.
The silver bar is also the page turn buttons, and up/down change the pages just like left/right. The bar is placed rather low for a page turn button, but it seems to work okay. I think my preferred way to hold the Story HD will be with my thumb to the north of the bar. This will let me click the bar with the side of my thumb in order to turn the page. This should let me keep a good grip on the ebook reader.
I just pulled out a Kindle case I wasn't using and the Story HD fit. It's ever so slightly too wide, so it's not a perfect fit. But that's not important; the case covers up the power switch which means I can't use the case.
The screen is absolutely gorgeous, but I was somewhat concerned about image rendering. Iriver seem to be handling that okay. All the color book covers I tested rendered well on the Story HD. This is a software issue, not hardware, and I make a point to test it ever since I had my hands on the Hanlin A6 (which was bad at rendering images).
The resolution is astounding; I didn't realize the difference until I had the Story HD and the Kindle side by side. I'm looking at them now, and yes there's a difference. But I'm not sure I care. The higher resolution is great, but the standard E-ink screen is just fine. It's a screen that has been used for years and I'm quite happy with. BTW, I'll wager $10 that the next Kindle also has this screen (Sony, too).
You only have bookmarks, font size, and PDF reflow/zoom as reading options. The keyboard is largely a waste; you can't type notes or really do anything with it.
The margins are narrow , and the test has a ragged right edge. I like both details, but I can understand that some won't. There are no formatting options, so this might be a killer.
That's all for now; I have other things to get to (sorry). I'm not sure yet that it's as good as the Kindle, but I do think it's better than any of my other Kindle clones.
P.S. Ars Technica have a number of pictures, in case you're interested.