I tried out the game with the New Society cards a couple of times, but I felt that with all of them in play they made the game longer than it ought to be, seeing as how it already tends to be a bit repetitive. On the other hand, it's nice to have the game be a little bit longer so that buildings are a more viable strategic option.
The rule book states "Of course, creative players may choose to use some, but not all of each to make their own game and play in their own way." I decide to take this to heart and make my own custom card mix.
First, I exchanged all the old cards with their replacements as instructed. Then I added:
Buildings Firehouse x 2 Hospital x 1 Potemkin Village 3/8 x 1
Aristocrats Secretary x 1 Controller x 1 Judge x 1
Trading Wharf x 1 Saint Petersburg University x 1 Golden Donkey x 1
I thought it would be a good idea to beef up the building deck since it seems to me that buildings tend to be the stack to run out first. I also threw in another Potemkin Village just to get a little more use out of the building trading cards. At first I had included the Coffee House, but on playing with that mix I realized that it only favored the aristocrat strategy more.
Meanwhile I wanted to reduce the power of aristocrats a little, but I wasn't sure how to go about it. In my first draft I added five aristocrats plus one Black Market, thinking that maybe if it was generally easier for everyone to get aristos they would be less powerful. After playing it that way once, I wondered if "easier" might mean "less interesting." Thinking that a well-executed aristocrat strategy relies on getting both the high-value aristos plus some trading cards, I decided to only add in the more high-value aristos. I felt like this would make it easier to get a medium-sized collection but it wouldn't make it as correspondingly easy to get a large-sized one.
As far as trading cards go, I threw in a wharf to make shipbuilders a little more valuable, a building to favor buildings a little more, and The Golden Donkey because the picture makes me laugh.
Update: played one three-player game, and everything seemed to work nicely. The craftsmen deck ran out first, one opponent almost beat me with a building strategy, and had the game gone longer my other opponent probably would have won with a different building strategy.