The core premise here is a simple one: Stephen Fry wants to travel the US in the most British way possible, whilst analysing what life would have been like had he grown up there (after all, as he points out, he was nearly born in the States). Except, the reality is that the book is the notes of the TV show and - like most TV shows - they had a limited budget and timeframe. On top of which, the US is truly gigantic. So what you end up with is an interesting, top-level documentary about the various states (almost all of them, at least) from the point of view of someone who has an eclectic image to uphold and a TV producer who wants to make interesting television.
As a result, the deep thoughtfulness that Fry is definitely capable of is largely absent, and the initial premise of soul searching is particularly paper-thin. Nor do you get any decent insights into the individual states themselves, nor the cultures they contain. I think this is best summarised by the opening to the chapter on Ohio (which mainly talks about the state's official beverage - see notes below - and Neil Young. That's it...):
I wish I could tell you of great adventures enjoyed in Ohio. I am photographed at the state line and... well, that is it."
There are moments where the book takes you to genuinely interesting extremes or absurd locations, but most chapters left me a little bored by the touristy information and disappointed at the lack of detail on some of the weirder elements. Still, Fry writes well and does have an exceptionally interesting point of view, which is infused onto the pages just enough to keep you, well, interested. Plus, being so large, the US is full of oddities and weird juxtapositions, which are precisely the kinds of things that both match Fry's public personality and TV ratings, so you do end up with some pretty esoteric information.
I've never seen the accompanying TV show, but I don't think it'll have any more substance than the book, particularly given the included photo pages. Whereas, at least with the book you get a bit more of Fry's dry wit coming through, so, for my money, I'd suggest it's probably the better of the two mediums. However, given the vastness of the subject matter and the relative thinness of the prose, I don't think either format would be particularly satisfying. If you're a big Fry fan or a huge Americaphile, you'll get a kick out of it, but I'm not convinced it's worth too much notice overall.
Check out my reading notes here.