The hex conversion, I'm not so keen on, but it's nice for people to have. I have the hex maps and will get more when i buy my third introductory box set for the minis.
The other one is cool to me, the Campaign system. Allowing games to be than just "kill all the opponent". And it allows for a story to be told. I like this even more in games set in a fictional universe, as compared to games set in historical. Sometimes it's hard to get out of the rigors of the real history.