If you own Power Grid, then this expansion should be considered. The China map requires whole new tactics, power plants come out sequentially and in short supply – so bidding was often above the card vlaue. End game resources were in severe short-supply, and buildings had to be well planned.
The Korea map with the split market certainly added a new dimension – everyone favoured the South Korea market at first, which pushed up costs quickly and the North Korean market (with limited and expensive resources) suddenly didn't look so bad!
These are challenging maps and sufficiently different from the original Power Grid board to make this a worthwhile addition.