I have taught out of previous editions (3rd, 4th, 5th) and it was a pretty standard GOB textbook. It wasn't the most readable text, but it was pretty trustworthy as a reference book. The 7th edition is chock-full of materials -- which is great if you're teaching a 3-semester sequence of G, O, and B, but it's way overkill on what's truly necessary at this level.