I just started this last night.
Got it for $45 from CoolStuffInc, which is awesome when split 4 ways.
I didn't know what to expect from this; and was somewhat pessimistic about the whole "campaign" idea; because I like games that can be finished in one sitting.
But this was awesome. We got through 2 games last night; lost the first, won the second; so haven't seen February yet.
I was expecting things to only change after the first game; so I was surprised in a good way when suddenly, part of the way through the first game, everything changed. It was just very creative; and the components are great at making you want to see what's coming up.
If there's a downside, I'd say it was that it forces you to make early decisions that will affect the rest of the campaign. It seems like 1 bad choice after your first game could make the entire rest of the games much more difficult. Though of course the upside to that same thing is that it's very customizable; if you played the campaign again you could go a completely different direction.
I'm not sure about the replayability; because the surprises seem like an important part of the fun. One of our four members has played once before; so he has to try to avoid giving advice about choices based on such knowledge.