It is a must for any historian studying the period. It does, however, tend to focus more on the religious aspects and concerns of Spain and her monarquia throughout the period though. The Spainish Inquisition is covered in detail. His lastest publication on the issue is, understandably, more focused but this gives you a detailed summary. A good and worthwhile Read.
Kamen is extremely informative in his description of the golden age of Spain, with great detail on small and great occurrences alike, and is used for both A Level and university study. However the text is rather dense, with no pictures, so may be less useful as a light read. Sometimes the detail can become too overwhelming, and you do need to take a break! I would suggest the 3rd or 4th edition if you want the most up to date information.