When I compared the old and the new Player's Handbook, the first thing I noticed was the artwork. Sure, the old book (at least my edition) had some humourous cartoons in it, but this time, TSR have really gone overboard with it. The technical quality of the art is really very good, and is both imaginative and relevant (someone has gone to the time to fit the art to the subject matter).
The actual content is also encouraging, but it still needs work (3rd edition, anyone?). In some places, areas of the game system are not sufficiently explained (I know some material needs to be kept for the DM Guide, but still . . .), and the spell listings also need some more work with the more obscure spells. However, overall the content is good.
Realistically, you cannot afford to be without this book if you want to run any sort of AD&D adventure. It is simply essential (as is the DM Guide, and, to a lesser extent, the Monstrous Manual). However, although you may buy it for the content, you will learn to treasure it for the artwork.