I am self-taught and study through Noad's solo guitar playing.
Overall it is very good book. Of course, nothing is perfect. If you follow the courses on this book, and get some help from YouTube and this forum and other websites, you can learn.
There is one thing that is very different in Noad's book to other method books: Noad does NOT teach based on scales. He teaches based on positions, so you will not practice scales and will not learn what scales are based on this book, but you will study progressively from position 1 through 9. The book has a few pages briefly explaining scales, but again, does not give practices based on scales. I can't say if this is good or not, but this is what it is.
Another thing, that I wish was better, the book does not give you very much practices pertaining to position studies. For example, it teaches position 5, but the pieces that it brings after this lesson are mostly in positions 1-3, perhaps with one or two measures only in position 5, and in some pieces none. So, you learn the positions, but will not be provided with enough pieces in each position at all.
Nevertheless, overall, it's good book and I do recommend.
Shrear's book, I just have the first book, and have not seen next ones. It is very detailed with a lot of emphasis on correct playing. Seems to be a good book, but again, I haven't seen rest of the books.