I ended up buying this after finding the first volume in a physical store, and I'm glad I did, as they hardly feel complete without each other. They're an excellent resource, just as much for information about the different units available in the game as they are for actually recognizing minis you might have purchased some months ago and can't quite remember what they might be. It doesn't happen a lot, but it happens just enough that a tool like this can be as helpful as it is novel.