I've got mixed feelings. I wanted a quick-start refresher and this looked like a good option, especially as it's one of the few spiral-bound books I could find. (Side note: Why is that? Spiral-bound is so much easier for music books!)
It started well, skipping tedious details of musical theory and explaining just the bare minimum to get someone actually playing something, quickly moving on to some chord basics and recognizable songs, but then it started losing me. I'm not a novice at this, so I really didn't expect to be confused by the explanations. (Maybe if I'd been able to spend time listening to the lessons on their website too it would have helped more, but it was hard enough to get 2 octaves on the piano away from my toddler, let alone the piano *and* a laptop...)
I'll also admit that I don't do well when people give instructions and don't explain what they are. Use C or C7 by all means - and both were explained - but don't go into Dsus4 and never explain what that means. It's like telling a beginner to type lines of code and then wait another 2 weeks to explain what it actually meant.
I might check this back out again and try again later.