I saw this book several years ago at the Tate bookshop, while browsing after an exhibition, but dithered. My interest was re-awakened by Kevin McCloud's series on The Grand Tour and I acquired a second-hand copy.
Whereas McCloud's series, understandably enough, focussed solely on the architecture to be seen on the tour, this book takes a much broader perspective, discussing logistics, means, and all manner of activities undertaken by the tourists. One theme that emerges is that many considered the continent - naturally - to be much less advanced than Britain - though Black intersperses the copious quotations from tourists with the odd one here and there about similar topics in Britain, with similar complaints. Their accomodation was fetid, the roads were poorly maintained, the food wasn't prepared properly - and so on. It's amusing (although it could be that it's been written consciously or sub-consciously with this perspective in mind) to see how little our attitudes have changed in some ways.
Ironically, perhaps the most captivating section of the book is the epilogue, which deals with the circumstances of the French Revolution and the Napoleonic period, and the ending of The Grand Tour. This includes a lot of first-hand material from Britons staying in Paris and elsewhere in France at the time.