As others have reported, the KitchenAid looks great, seems to be well-built, and overall, is well designed and implemented. In my household, this machine replaced a low-end DeLonghi burr grinder, and the results in comparison are superb; the consistency of the grind is far, far better.
As someone relatively new to espresso making, I'm probably not yet qualified to fully comment on the quality of the grind for espresso, as this is the only grinder I've used that is capable of producing an espresso grind of any kind. What I can say is that I have been able to produce excellent quality shots with coffee ground by the KitchenAid, and at the end of the day, isn't that what it's all about?
That said, it can take some tinkering to "get it right" (which I understand to be true of any grinder). Some have found it difficult to get the grind fine enough; in my case, I've succeeded on numerous occasions at getting it too fine to pull a shot (after following the owner's manual directions on setting the grind as fine as possible).
There are a total of 15 grind settings in the Kitchen Aid; 1 through 8, with half steps in between. Unfortunately, this isn't quite enough. As some others have reported, for example, on occasion a setting of 8 can be a bit too fine, and 7.5 slightly too coarse (or at least it seems that way). I think a better approach would have been removing the detents completely, and allowing a continuously variable grind setting.
All of that said, the KitchenAid does seem to be perfectly capable of generating an espresso grind. Once it's done so, however, there's the matter of getting it into the portafilter. The best method I've found is to spoon it (with a teaspoon) into the filter, and tamp. I have quickly discovered that anyone who makes espresso more than a couple of times day, however, could easily grow tired of that routine and long for something better.
Other observations include ease of cleaning; it's a simple matter to take the machine apart and sweep or vacuum built-up grinds from the burrs and other internal parts. The glass containers (both the hopper and grind container) help reduce static electricity build-up, thereby reducing coffee bits seeming to jump around the kitchen counter. And its seemingly robust construction (time will tell, of course) is both functional and handsome.
Everything here being said, I'm not sure I would choose this again. For low-volume espresso drinkers, or those who primarily drink drip or French press, the KitchenAid is a wonderful choice. But if you regularly make espresso drinks, or consider yourself an espresso connoisseur, you'd probably be happier with something else.