I have studied Lowland Scots for about four years now (casually, not academically) and I can say this is the least favorite of any book I've purchased on the subject. If, like me, you are looking for a book to deepen your knowledge of Scots then I don't recommend it. If you are unfamiliar with Scots, you will stumble over the Scots words and will be frustrated to find there's no glossary.
Although there are some really funny bits, this is a selection of qoutes by Scots, not Scottish sayings, and it doesn't lend one drop of understanding of either the people or the language because in reality, anyone from any culture can come up with an insult or witty retort, and if it is not unique to the culture (as the title leads you to believe) then why bill it as thus? I see no point in making a collection of such if it doesn't shed light on Scottish culture at large. It doesn't help that most of the selections are obscure at best: does anyone reading this know who or why Lord Macaulay would have a reason to comment on James Boswell? Or Alexander Trocchi?
If you're familiar with Scots and looking to learn more, then don't purchase this book. It's not worth half the price for research. You're much better off looking up an old copy of News Out of Scotland or The New Complete Patter, a Glaswegian sampling of colloquialisms that will lend you a much better use to the language than this selection.
If you're not familiar with Scots and are interested in learning the dialect, then this is not the book for you. You're much better off with a book of Burns and a Scots dialect dictionary (kill twa birds with yin stone, I say) or for a quick read on Scottish sayings (both Scots and Scotland at large) then I suggest you buy Haud Yer Wheesht and Allan Morrison's other selections which are quick reads and will help you decipher those baffling colloquialisms.
If you're Scottish, then you may like it just fine as a collection of historical interest, but as a collection of insults, one would be better off with Acid Drop.