I've got an initial review of the Stokes guide up on my site. A more detailed review will follow, but here are the highlights:
On average, it includes 4 photos per species. This is fewer illustrations than Sibley, for example, but for a photographic guide it's a lot - on average more than any other photo-based guide for NA. And it gives just as much coverage to the rare and range-restricted species, something that many other guides don't do (Smithsonian and, especially, the Princeton guides, for example).
The Stokes guide is very attractive overall, with great, fairly large photos and a good layout. I'd say that the Princeton guides are the only ones more attractive, but they don't include as many photos per species.
The text is ok. I like the attention paid to shape. However, I wish that a behavior section was included. Notes on important behavior (like tail-bobbing) is included, but buried within the Adult plumage description. The section on subspecies is fantastic. Personally, I'm going to be using this a good bit to double-check ranges.
The range maps should be about the same as those in other recent guides (all use data from Paul Lehman). I do wish they were a bit bigger, and the dotted lines can be hard to see.
Overall, I like the guide. You could carry it in the field if you have some sort of pack or a very large pocket. But I think the main purpose will be as a photographic reference for your car or home. For now, it will probably become my general photographic guide of preference.