I have very little patience with books these days.
This book wasn't terrible but several things bothered me. The constant interjection of Latin words and phrases in the vocabulary of the Sicari (it didn't seem Italian to me). English is my second language and I seldom interject random Spanish words as I speak. This drives me bunkers when it's done in books because I've NEVER known a fluent speaker to do that (if your English is good enough in the first place, then you speak English to people who speak to you in English.)
Something else that bothered me was that there was a constant comparison about what the Sicari do and what the Praetorians do. Maybe this gets less as the book goes along but I just didn't have the patience to find out.