This is close to the perfect bird guidebook. This Sibley guide is more detailed than the National Geographic guide with a true bonus of more than one excellent plate per bird. In flight views are excellent, all the views you require, it appearing to be an amalgamation of the peer referral milestones of birding literature. The families are grouped together with even the female 1st winter plates on the same page clear & as are the birds in the field appear. Distribution maps and song & call details are much better than any previous attempt in any fieldguide including European bird field guides. Tips similar to advanced birding literature are subtly added, the book becoming a true educational tool, the ideal book teaching you without one realizing. Certainly the format of the illustrations are of the New breed of Bird illustrators not perfect feather detail but as it appears in the field & for that to the majority of field workers ideally adequate It will fit in a backpack but unfortunately not pocket size, which is not practicably possible due to wealth of information bound into this New milestone of Literature .I personally would take into the field as quick referral to a Foreign country's birds with thoughts of how useful it would have been to a Spring trip to Point Pelee some years ago. Every Birdguide will now have to reevaluate their presentation after this excellent 5 star performance