I have not seen the STARZ TV show this book is the account of making, but this book (and the audiobook specifically) was a pretty good time. (STARZ insisted on naming the TV show Men in Kilts, but its original name was Clanlands, as this book makes pretty clear without actually stating it.)
If you want something extremely goofy, spotted through with Scottish history, this is your book. The book is told by both Graham and Sam in alternating POV sections as they narrate the process of getting their TV show off the ground, and the actual behind the scenes experience of filming it, along with Graham’s ecstatic recounting of historical facts as they visit each place. There is also a staggering amount of alcohol drunk, and some fun behind the scenes stories about Outlander. The real star of the show, though, is their friendship. There are moments of genuine affection, but mostly it’s both of them taking the piss out of each other for several hundred pages. YMMV on their jokes, of course, especially some that could be taken as sort of sexist, but overall it read to me as pretty harmless. (The biggest example is that Sam refers to Graham as Lady McTavish, because he has high-end tastes and specific food and comfort needs, and is less prone to danger seeking than Sam is. I got the feeling this was more about class than gender, but again, YMMV.)
If you’re going to read this, you really have to do the audio. The writing isn’t a showstopper, but their performances bring a lot to the table. Graham McTavish in particular is a very, very funny human being, which I already knew from watching approximately 1,000 hours of behind the scenes footage from The Hobbit trilogy. I think I would have enjoyed the book a lot less if I’d read a hard copy.