I just received my copy of the expansion today and promptly tried it out. The first thing to notice is the quality of the box itself. If you own the 2nd edition of the base game already, you'll know what I mean when I say that the box is of a much higher quality than most other board games. Inside is everything listed in the description, but there are now designated spaces for all of the petri dishes, pawns, research stations, cards, and the various wooden tokens used in the game. It also has extra spaces for what I can only imagine will be coming in the second expansion, In the Lab, due out in August. This is a quality product from Z-Man Games.
The game itself... if it wasn't addicting enough already, the expansion allows so much variation to prolong the fun. My sister and I have played the game to the point where it was almost impossible to lose on normal, and we were able to vastly tilt the odds in our favor for heroic difficulty. Now our strategy doesn't work as nicely, and there are so many more factors to take into consideration. Further, there is now a legendary difficulty for an almost impossible challenge (challenge accepted).
Overall, I am very pleased with this expansion, and I look forward to what is coming with In the Lab!