This is going to be a short review as after being only 80 pages in I just stopped reading in disgust.
The style of writing (which is first person), doesn't agree with me at all and after reading so many pages I didn't care about anything that happened.
The characters are boring and unlikable, but the worst part is the plot. Stuff just keeps happening without rhyme or reason. This does fit with the theme of the plot (the protagonist lost his memory and slowly recovers it), yet the execution is so haphazard that it reads like a 'And then this happened, and then that happened'
To give one example; the protagonist discovers early on he has a lot of brothers and sisters, most of which, he also discovers, he didn't see or hear from at all for years. Yet in the span of fifty pages he somehow manages to run into a number of them. They just keep popping up.
This book is what you get when an author just puts his pen to paper and begins to spill his creativity in an endless stream. I'm certain there are people who enjoy these things, but I'm not one of them. Especially not considering there are ten books in this series.