I got this books 1996 edition in 2007, and I loved it. I recently bought the second edition and I have to say that it is very improved and more user-friendly than ever.
Unlike the first edition, text is in front of the plates, which makes stuff much more easier, especially for a beginner. The other difference is that the maps are coloured to show where species breed, winter and/or appear during migration.
Majority of illustrations have changed, including larks, wagtails, majority of gulls, skuas, terns and almost all of waders, and much more! While some of illustrations are more detailed and easy now, some of are not, e.g. illustrations of larks and warblers now being almost gigantic, which covers the whole page.
Over 130 species and subspecies added, which I'm not surprised, it's very normal for a book that first published in 1996.
One of the biggest and hardest change is that the order of species have changed, starting from gamebirds and ending with buntings. I was expecting that it would start with gamebirds and wildfowl (which I was true) but the passerines are messed up too! It starts with shrikes, then crows, tits, larks, warblers, starlings and it goes on like that... I kinda hated this new taxonomic order, but it's obvious that ostriches and kiwis are more related to gamebirds than divers.
Also, some explanations, tips and information about identification, life cycle (...) in gulls, just like Collins Bird Guide.
Overall, the second edition has some kind of more "modern" look. But this doesn't mean it's perfect...
NEGATIVE WAY NUMBER 1- Illustrations are really cool and detailed but I think it could have illustrations about species habits, too, e.g. it could have an illustration of Osprey catching a fish, and it could write below "Oprey catches fish" or something like that. But in here, we only have one illustration of male, one of female, juvenile and an adult or juvenile in flight. Some species don't even have flight illustrations! And there are also lack of sexes and subspecies, e.g. Lapwing appears all year-round in the region, but they only drew the winter plumage. This also happens for subspecies, immatures, females and males.
NEGATIVE WAY NUMBER 2- Text could be better, especially of two very similar species e.g. spotted eagles or common and lesser kestrels, but text is generally OK.
NEGATIVE WAY NUMBER 3- There are no maps for vagrants, so vagrants have a section in text called "Notes" (some breeding, wintering and passage species also has this section, if they are vagrants in somewhere), and it writes about where the species have been accidentally seen. Unfortunately, some of these "notes" are wrong. There are photographs of Lesser Flamingo photographed in Turkey, and this guide still didn't write that it appears as a vagrant in Turkey. Same thing also happens for other species and other countries.
Well, that's all what I'm going to say. It is a vey good field guide, and much improved than 96 edition, but if you have Collins Bird Guide or anything similar to that, you won't need this book much.
Hope I helped.