Good, but not as good as I hoped. Unfortunately.
The premise seemed very intriguing, a story with a bizarre/dark twist (like Edward Scissorhands for example)
But this, well...

The book starts in 1874 Edinburgh, some descriptions of events that happen cannot possibly be known by the characters in this time period. For example, during the operation on his heart as a baby (don't even get me started on how as the first person narrator, he'd be aware of his own birth!) he says the surgeon/midwife has "her arms in the air like she's just scored a penalty in a World Cup final." Now correct me if I'm wrong but didn't the World Cup begin in the 1930s? How could he possibly know what that is? And it continues all the way through with references to prostitutes in spindly stilettos and animal print (really?) and Jack the Ripper (how could he be in Edinburgh when at the same time he was in London committing murders and why would he confess to a little boy?) Arrrggghhhh!!

Honestly now, this was a really promising storyline that fell quite unfortunately into a bad writers hands and suffered because of it.