Well illustrated pictures and for the keener bird watcher, it's got all the species. The maps are clear, though not always near the pictures/text. It is confusingly classified (not the standard order). Naming follows the American system which is also confusing. In the area bird watchers will refer to species by their English names, so Grimmett is not helpful in this way. It would be better if it included commonly used names as well. An example of the confusion is with what is commonly called the 'blossom-headed parakeet' Psittacula cyanocephala. In Grimmett this is called the 'plum-headed' and, more confusingly, there's another called the 'blossom-headed' (P. roseata). Also, nobody in India seems to call a purple moorhen a purple gallinule.
However, it's a good all-round book. Combined with another which has the ordinary names and a bit more information, it was a good choice. (I took Collins Handguide to the birds of the Indian Sub-continent as well, which gives more info about the more common species).
I hope this review is helpful.