The biggest change in Brave New World is probably the trade and the love gold. Besides luxury resources, there is practically no more hexes with gold. This is a hard blow in the first moment and meets especially the warmongers at the beginning of the game among us who look at an ever faster becoming empty purse with increasing troop strength. The answer is trade, because - joy! - There are again trading routes that are traveled by caravans and cargo ships. The farther the other town and equipped with different resources, the more dough to be flushed into the cash register. And the harder they can be protected: trade routes attract marauding Barbarians and enemies magically - to invest a portion of the gain in military units is not the worst of all plans. In addition, some subtleties with the trade routes involve: beliefs, influence and scientific knowledge thus spread also. What I really like is the ability now to transport food or production in other cities. Thus some stunts with the urban planning can fabricate that were impossible in the previous version.
However: After the first few hours, I feel that the biggest warmonger with the introduction of the trade routes have become suddenly very tame itself. The threat of financial loss, the financing of the army and other bonuses that no longer exist are suddenly ... where previously the usual suspects have at friendly neighbor visits and cities looting the latch itself into my hands, suddenly there is sunshine and roses. A whole game alongside the French and not a war? Alexander with wreath of flowers in her hair and quietly "peace on earth" sighing? The peaceful coexistence is ... suspicious. Well, maybe the lugs are also more reasonable geworten - you do not know.
The next major change concerns the "social policies" and the cultural victory. With culture you buy still Social Policies which are assets of all kinds, but these are no longer directly into a cultural victory. Tourism and the impact on other nations is now decisive for. Tourism you get through images, documents and music that you can exhibit in their own museums and wonder. Practically, that the great personalities writers have been added yet and archeology: digging for ancient treasures, this nail on the wall and is good.
Of course there are a lot more new things, too much for a short review. My first impression is: A strong buy recommendation - this extension rocks and makes my opinion the best part of Civ 5 in the series Civilisation.