It's a nice book to drift away in. It's effortless in its ability to transport us to early 19 century Britain. 
But it's also kind of aimless. It's very long for what effectively is a man making a journey, friendships and then a second journey. But maybe that pacing is part of it - it was a slower time.

But does it work as a book, what does it say? I'm not sure. Maybe that we are sometimes defined by the things we don't do or say. The hero is someone who, in drunkenness, allowed a mass of war crimes to happen without making an effort to notice or stop them. He goes on to become someone who almost loses an important relationship because he lets too much go unsaid.
The end is incredibly unsatisfying. They are free because they are drowning, having overcome the hurdles before them, they simply give up and float away. It felt very tacked on.