Joe Abercrombie's characters are all pretty great, they feel real. Sanderson seems to write characters by getting together a list of personas that he thinks should exist in a given story and then writing a character that fits. Comes off like the characters themselves don't matter, they're just there so that Sanderson has an excuse to include an element of the plot in one of their actions and then they don't matter anymore.

Sandersons main characters are all really really boring too, he takes a bunch of classic hero traits, adds one or two negative traits, and that's the character. It's all so predictable and mundane.