I think Saul's book is a great attempt of bringing a complete IPSC technical guide in a compact format. Technically speaking, IPSC is a simple sport, and Saul's book showed me that. Great drills. By the time you master all of them, you'll be a pretty good shooter
I think that Brian's book and Saul's book is a combination that is hard to beat.
I have seen Steve's book. It looked great. I didn't buy it because, well, I already dry-fire a whole lot, and I don't want to raise the staus of dry-fire to a realm of it's own. Dry-fire is there to support my live fire. If I would get involved in the matter of dry-fire even more, it would be like I'm shooting two different sports. IPSC and dry-fire
But that is personal. I'm kind of obsessive like that I guess