This book's real name should have been "Passerine of the Palearctic". It might not be as commercial, but it would clearly show the amazing work that has been done by Normann Arlott in bringing toghether, in an uniformised way, all the birds of the northern Old World (a second volume covering the non-passerine is in preparation). And mind you, his Palearctic approach includes all the islands (from Cap Verde to Riyuku), the whole Arabic penisula and best of all, the whole Himalayas, including the southern slopes towards India and Burma... European and Japanese birders, who are spoilt with excellent but more local field-guides, can finally get a real appreciation of the species diversity in each group, and it's a delight!
True, there are still many way's to improve such a work. Having the (very interesting) map's at the end of the volume is not optimal, the treatement of subspecific diversity is some time surprisingly incomplete, the drawings, while acurate and perfect for comparison inside the groups, are typical of the author's style which is slightly stiff in my view, and there is minimal information on field ID (nothing on juveniles). But this information is available in many other books, and does not deter from the appeal of this volume, who is much-more then a check-list and brings together for the first time and for a very reasonable price most of what Marco Polo would have needed, had he been a birder...
So whether you plan to travel or are still in the dream phase, sit down, relax, and wander through the plates, recognising the species you know (or even have seen) and discovering the (many) others, that are still waiting out there to be observed, appreciated and protected!