Robert Hand's book
Horoscope Symbols has received mixed reviews, and as you note, Robert Hand has "moved on" in terms of his astrological development and views. That does not mean that Horoscope Symbols is not a good book, it means that his interests have increasingly turned to historical research and the application of ancient astrological methods to interpretations done centuries ago and their possible usefulness today. In that research, he has also been criticized for not being more even handed in his search for material and its interpretation. But, this may be a critique that doesn't recognize that one can only do so much at any one time --- we can't expect him or anyone to provide a broad front of research and interpretation on a constant basis.
As noted by both Minderwiz and myself, Aspects in Astrology by Sue Tompkins is a very modern and well written book that one can use as a lifetime reference, as is Ebertin's CoSI for applying 3-planet midpoint structures for interpretive uses---although the latter is more a reference book than a reading book. Still, other books by Ebertin are quite striking if you like a modern approach. Dave