I love Cooks Illustrated, and these books are very much written in the same vein.

I should point out that I wrote these reviews before I got comfortable with replacing dairy products with whatever I felt like replacing them with, so as written, the first book isn't non-dairy friendly, but the recipes may still work with some tweaking. For example, the chocolate chip cookies, brownies, and blueberry muffins all call for melted butter, which makes it super easy to replace it with (slightly less) liquid oil.

So it's possible you can make other recipes work dairy free, but, of course, you'd have to do all the work yourself. At least in the second volume they do it for you.