First, the good: all of the blocks are designed to be the same size, so you can mix and match them as you please. This is a considerable help. I have a number of vintage crochet-block books from the 60s and 70s, and none of the blocks are the same size, so it takes a lot of tweaking for each block if you want to make an afghan.
Another plus is that the publisher is Interweave, which has a solid reputation for producing excellent fibre arts books.
Next, the bad: the title is misleading as there are only 138 blocks, with colour variations making up the rest. There are even fewer blocks if you omit the single-crochet ones with pattern variations (e.g. thick stripes, thin stripes, blocks divided by colours into halves or quarters).
There are no charts, which would've helped immensely when the instructions get confusing.
There are many, many errors. Some of the mistakes are obvious and can be fixed if you look at the photo carefully, but for the others, you just have to make it up as you go along and hope that the block turns out okay.
Also unfortunate is that there are no stitch counts for each round or row. Without charts or stitch counts, it's hard to tell if you've made an error. The lack of stitch counts becomes downright annoying when it's time to join the blocks. You can't assume that every finished block has the same number of stitches on each side, so when sewing up, you have to rely on counting, re-counting, and averaging.
There are no photos of actual finished afghans, so you have to experiment to see which of the 3 joining methods looks best.
Other comments: in the end, despite its shortcomings, it is worth having this book in your collection, simply because it is the only one of its genre available. I would've given the book 2 stars if it weren't for this point alone.