From what I have gathered they were well received books at the time of their release, but they are a little dated and I'd like to know how much they still hold true. The books are The Greatness that was Babylon by H.W.F. Saggs, Egypt of the Pharaohs: An Introduction by Alan Gardiner, The Hittites by O.R. Gurney, and The Persian Empire by J.M. Cook. I was thinking about returning them if they were too out of date as they were quite expensive.
I also have two follow up questions.
Why do all these books use footnotes instead of a bibliography?
Why do most of these authors use their first and middle initials followed by their last names instead of their first and last names.
Saggs was definitely a very well-respected scholar in his field, and his books are one of only a handful of reliable attempts at a general synthesis of Assyriology for the layperson. That said, his work is obviously dated by now. These days we know much more about the early periods of urban development in Southern Iraq (esp. the pre-Ubaid period) than Saggs did, and he subscribed to some theories on religion (like Moortgat's interpretation of Tammuz as a death-rebirth archetypal deity, or the possivility of human sacrifice in the burial at Ur's royal cemetery) which aren't really in vogue any longer as far as I can tell.
There are a few minor factual mistakes as well and I do wish he'd been more forthright about his sources, but overall you can hardly do better than Saggs' books for their breadth alone.
As for "why footnotes?" I suppose they were intended to be more accessible to a nonspecialist. I have no idea why all those authors abbreviated their names in the same format. It must've been fashionable.