This is a game I too wanted to really like, but couldn't quite for many of the reasons put forward by Valamir. I found it to be decent, but not great.
I think getting the amount of table talk right is very important to enjoying the game, but the rules provide frustratingly vague guidance. Specifically, I think you need to have a lot less than what fans of Knizia's Lord of the Rings may be used to; communications should be kept quite vague. For example, I don't think that you should be able to mention specific cards when trading with Arthur, although trying to work out what might/might not be allowed by the rules in this case becomes a maddening exercise in trying to channel the designer's poorly-communicated intent. In practice, I think a given play group will have a preferred style, and if your style happens to match the designers', you're good, otherwise, there may well be balance problems and there likely isn't much you can do about it.
Whether or not the game is actually interesting with a much lower level of player discussion than Lord of the Rings is a separate question.
For me personally, Shadows has too many annoying deficiencies when compared to Lord of the Rings to really succeed. In Lord of the Rings, the different boards (with something of a reset button in between) prevents bad luck from spiralling out of control, which has lots of beneficial side effect - in Shadows, once you're on the reverse slope, you seem hosed and the game gets pretty tedious. The concrete communications rules in Lord of the Rings don't hurt your brain just to think about. The more flavorful and varied events give a much stronger theme, and the event tracks (as opposed to random card draws) let you do more interesting planning. The endgame is more exciting than the grinding affair it can be in Shadows, with too many players spending too much time fighting holding actions and not enough actually driving the game.
Shadows of course has the Traitor, which is quite cool, but for me that doesn't cover for the other problems.
Anyway, I have a review of my own which you can find
here and which I've been meaning to submit to RPG.net also ...
Chris