1) Definitely dense, but with a lot of action. I think Erickson did a fine job introducing us to his world without too much exposition. Granted, it was a little confusing in parts, but by the time things really came to a head, I had it pretty well sorted out.
2) His characters are fairly strong, which is good since there are so many.
3) The balance of the "epic" scale was a little skewed. It was really hard to tell which God or God-like being was going to suddenly be more powerful. In this it reminded me a bit of Dragonball Z, with the characters suddenly powering up and showing new hidden strength, but with Malazan, it was harder to tell which was actually more powerful. Perhaps further reading will reveal that balance a bit more.
4) Meh... I'm bored of reviewing. :)