I was wondering the same thing myself. I know it's unscientific / biased, but I usually take a quick peak at the Amazon reviews. Here's the summary, in case it helps anyone else:
- Programming Voice Interfaces = no reviews
- Mobile App Development with Ionic = 3.5 stars (3 reviews)
- JSON at Work = no reviews
- Refactoring JavaScript = 5 stars (2 reviews)
- CSS Refactoring = 4 stars (4 reviews)
- Interactive Data Visualization for the Web = 5 stars (16 reviews)
- Learning React Native = 5 stars (2 reviews)
- Learning HTTP/2 = 4.5 stars (7 reviews)
- SVG Animations = 4.5 stars (8 reviews)
- Working with Static Sites = no reviews
- React Native Cookbook = no reviews
- CSS: The Definitive Guide = 5 stars (13 reviews)
- Using SVG with CSS3 and HTML5 = 5 stars (1 review)
- Learning React = 4 stars (22 reviews)
- High Performance Images = 5 stars (1 review)
The sample size of reviews for most of the books is a little limited, but I'm planning on picking up the bundle at the $15 level anyway -- CSS: The Definitive Guide is well-reviewed (and expensive by itself).
