If The Lies of Locke Lamora was great and The Red Seas Under Red Skies was okay-ishly good, I would rate The Republic of Thieves as passably adequate. Action packed with a few perfectly executed twists, some commendable skullduggery, some childish mistakes and about 700 pages later, you are still left with nothing but a feeling of "meh". Don't get me wrong, this is definitely not a bad story, great in some parts but equally slow, tenuous and just plain frustrating sometimes.
Sabetha, the character that was teased and hinted at continuously in the first two books takes a center stage here. She is a bad-ass no doubt - smart, cunning and a bit savage. She makes our protagonist, Locke Lamora, behave like a one year old cry-baby whose bottle of milk has just been snatched away. This is all fun and games in the beginning, but then even after about 400 pages or so, when you still find them doing the same "dance", it starts to get repetitive and circuitous. I do believe length of the book is an issue here.
The past story arc is about 17 year old Gentlemen Bastards told to run their first real "job" while pretending to be theater actors. The present story arc takes place in Karthain, the city ruled by the spooky, gritty Bondsmagi. Locke is tasked with rigging the city-state's election in favor of one political party. Sabetha has the same task - but she represents the other political faction. It would have been great to see this Locke vs Sabetha game. But the slow pacing, a couple of ridiculous twists and the fact that the past story arc is better than the present one makes this a messy affair.
Overall, I would give it a 3/5. Passable - yes. Great - No. Perfectly adequate.