Very right, though it does changes, most of the core remains much similar, but the newer editions often carries definition of many more new terms-which ain't new in the real sense- and gives it a more directional definition, and such things as expanded bibliographical coverage. The latest edition often also carries more sources and legal citations. I have almost 7 different editions here with me, but I believe there is a easy android app always updated on the Android app ecosystem. I think that is great.

So, Yes its worth it @markwhittam. Thank you.