Both texts are complementary, and the student should not suffice with one or the other. While Hidayat al-Nahw is organized in a very logical fashion and presents the rules of nahw in a very concise manner, giving the student a mental layout of the science, it is lacking in examples and practical implementation of the rules contained therein. This is where the al-Nahw al-Wadih series comes in. Although the series does cover more or less the same rules contained within Hidayat al-Nahw, it does so in less structured manner. However, it is replete with examples and exercises, and coupled with the answer keys that come with the books, would be a great, perhaps indispensable, supplement to work through concurrently with one's study of HN.
http://www.fadakbooks.com/alalele.html) or the "Thanwiyya" (http://www.fadakbooks.com/alalale.html)?
The entire series.
Thank you for the clarification.