I'm enjoying Dishonored (I'll leave the 'u' out, because it's the title of a work, but I am not happy about it) so far, but I hear what Yahtzee's saying. I mean, personally, the only reason I reload when I get caught is because I'm trying for a pacifist-ghost run-through for trophy purposes. Not that I'm a trophy whore or anything, but because I actually wanted to see how difficult that made the game.
But there's nothing particularly engaging about the characters. The Loyalists in particular are about as characterized as a cardboard cutout. It's like they put so much effort into creating the world as a whole that they forgot to populate it until the last minute, and then had to rush through it.
Considering Arkane has only developed three games including this one, (and disregarding the art work they did on Bioshock 2), it's definitely not a bad attempt. I'd like to see it get a sequel, if only so that I can explore the world again with a more interesting population.
Also, I have no opinion one way or the other about silent protagonists, but I found it weird that they gave Corvo so much back story, and then didn't give him a voice. Probably a casualty of the moral choice thing.