I have taken a couple of graduate level courses in quantum mechanics and I have decided to read Sakurai's Modern Quantum Mechanics from cover to cover, partly because I liked his style and I have heard a lot of people talk highly of it. But I recently realised that the second edition of the same textbook is quite different from the original (revised edition). The second author wrote a whole new chapter on relativistic quantum mechanics and rewrote several parts of the book (a complete list of changes can be found in the preface to the second edition). Comparing, it with the original, I found the original a lot less uncluttered and better organised. Is it a good idea to ignore the second edition and stick to the original? I am very curious to know the community's opinion.