It's basically just the lecture notes for their class bundled up into a book. I took the class it was based off, and, well, it was okay but not great.

It lacks any sort of underlying narrative or structure--I think this is common with algorithms texts in general. Probably why I didn't like the course much. It feels like a bunch of disjoint topics held together very loosely by some techniques that get repeated a bit.

I compare it very unfavorably to Sispser's Introduction to the Theory of Computation which, I felt, was much more coherent as a book. It's not a fair comparison at all because they're about different (although related) subjects, but I think it neatly illustrates my point.

Also, I don't believe Sipser's book is free, so it's not entirely relevant in that sense either. I just brought it up because I think it's the best example of the underlying narrative and structure I was talking about.