I also have Tim Taylor's book.
In my point of view, this book is clearly the best I've read on the Bird's opening, and by far. I think that the best point of the book is that the author knows what he is talking about, as he is a regular Bird player.
But I also think that many lines are missing. For example, there is only one game dealing with the line 1.f4 d5 2.Cf3 Cf6 3.e3 Cc6. yet this line is the most frequent of bird all variations. Taylor considers this line as dubious, but gives no way to obtain an edge with white ! I am quite confused.
Another strange point : the Bird database of Mr Taylor seems to be really small, as he often say : this line needs practical testing. But in my database, (big Bird Powerbase) these lines have already been tested !
I also don't understand white the author gives a whole chapter on the line 1.f4 e5 2.fxe5 d6 3.exd6 Fxd6 4.Cf3 Cf6 5.d4 Cg4. Yes this variation is quite complicated but it doesn't occur too often, one game was clearly enough.
And these are only a few examples of strange or missing points in the book.But as I've already said, I think that this book is the best on the Bird, so all Bird's players should buy it !