One of the arguments among the creators is how much math/logic to put into the graphic novel. The winners in the battle aim fairly low, deciding to focus more on character. And certainly Russell is an interesting character, as are some of the other celebrity mathematicians who make an appearance. The novel tends to focus on the insanity that seems to go hand in hand with mathematical philosophy, and it's hard to dismiss the connection when you see the vast assemblage of nuts (or at least familial insanity) that are important to the story. Logicomix is not meant as a textbook or a history book, so it's unfair to judge it as one (though it does have an excellent glossary!). But I did feel a bit disappointed in the presentation of the ideas. Mathophobes may find this a plus.
So there remains the task of judging it as a graphic novel. I'm not a very good person for that task. I found it's meta-ness somewhat engaging; I enjoyed the story of Russell's life, though I'm disappointed to discover that some of the meetings portrayed in the book never happened. I enjoyed the allusions to the mathematics. But, as is my general opinion of graphic novels, the overall presentation feels shallow. However, my biggest beef is that I really felt let down by the finale, which attempts to draw parallels with the Oresteia. The story had built up some goodwill, but rather than a climax, I was treated to a poor and overlong analogy.
Here's a better review. It's better than mine, and reading it made me want to read Logicomix. Which means that review is better than Logicomix.