I love it because it is thorough and precise. The tab is accurate (it isn't always with some books) and the music notation complete. There is even a key at the top of the page to give you the tuning if it is altered. The tutorial, while sounding a little sterile is very clear and extremely well executed. Other reviewers, I believe, are understating the level of difficulty somewhat. Having studied classical guitar, I found the pieces here well within reach, but I find it a stretch to say that they would be aproachable by a beginner, even an advanced one. Now, why I hate it: From reading Weiser's (the author) bio I learned that he is a classically-trained guitarist only a few degrees separated from Segovia himself (impressive)and that his intention with his arrangements of Celtic music is to foster greater acceptance of it in classical circles. That's a noble enough cause, but when I reflect upon the arrangements here I have to say that some of them are almost too Baroque-sounding for my finger-picked, steel-strung and down-tuned taste. If, for example, you were looking for a John Renbourne or Martin Simpson-type of experience with this book, you may be disappointed. I think not, though. Predispositions aside, his version of Jock O'Hazelden is very nice and will fall quickly under your fingers. His Morrison's Jig is spot-on how a fiddle tune should sound and his Carrickfergus is richly harmonized. I've returned to this book again and again. If you want to learn some Celtic music for guitar, the sheer volume of material contained here makes it worth the investment.