As far as accessible language textbooks go, this one works incredibly! Turkish is a complex language that, while it isn't terribly irregular, comes off as almost totally grammatically alien to speakers of most Western languages, and this textbook, for the most part, explains things incredibly straightforwardly. While designed for tourists and other travelers to Turkey, this book works wonderful as a self-study textbook (that's what I used it for!)
Pollard does a lot of handholding through complex grammatical concepts and never assumes that the student has had any formal linguistic training which is wonderful for folks who are new to studying foreign languages. The vocabulary is arranged thematically in useful sections and progresses quickly but manageably and has a well assembled glossary in the back.
That being said, as someone with a fair linguistic background, I found that sometimes in an effort to be truly accessible, concepts that were relatively straightforward (especially phonological aspects) ended up being mystified or just ignored. A great example: vowel harmony is explained away as being governed by strange and esoteric rules that you just have to get an ear for then just leaves it at that. Vowel harmony is strange to a non-Uralic Westerner, sure, but it's hardly too complex to explain in a beginner's textbook and a pretty necessary part of Turkish grammar to understand if you're ever going to sound like anything but hopelessly foreign!
Aside from shirking some more complex concepts and some moments that felt dated (a whole chapter about phones and operators and nothing about the internet! It was adorable!) I think this was a wonderful introductory textbook. Highly recommend!