If you have 2nd edition then there is no need to buy this one. Some "more" addition is not beneficial for exam point of view. You just need an idea of some topic in AnC. More and more material (in AnC) is just waste of time instead use your time in some other subject/topic or in other work. In anyway no one suggest particular book for AnC because it becomes useless in mains and in pre it just ok but not good/best.
3rd edition is just amazing. It is so colorful and with current affairs and other chapters addition . After years I got to read such a colorful book with lot of picture . Thanks writers for making upsc journey enjoyable.