This is a pretty nice reference book, especially if you want up-to-date information on what is synonymus with what... it certainly doesn't appear to be all inclusive, but nearly so. Covers the Aloes, Agaves, Amaryllidaceae, Dracenas, Nolinas and 11 other families of succulents (all ones I'm less familiar with). Of particular interest to me was the run down on AGaves and Aloes, listing nearly all the species I was familiar with (no hybrids or clones) and providing brief, highly scientific descriptions of each species and its synonyms (many plants I hadn't realized were synonyms, too). Not sure
Eggli's taxonomy is the currently accepted taxonomy, and really I am not one to know. But it is a very useful book in describing what's what. Photos, however, are all in the back and only cover a few taxa sadly. Lack of sufficient photos is always my complaint about any book on plants, and this is no exception. However, it does have a some photos of very rare species in the wild which I have not been able to find anywhere else, so that's a plus. I checked this book out of the library and wouldn't really consider buying it.