Vincenzo is one of the best kdrama I´ve ever seen! An excellent cast for both good and bad guys, interesting characters and the whole story with balanced mixture of brutal action, emotions and smart comedy, not oversweetened romance, mostly logical script, sometimes a bit exaggerated but fun, nondistruptive flashbacks, greatly concieved direction and camera, top visuall aspect and overall setting, fitting OST. I appreciate the connection with Italy as I studied italian language for some time. My first rating was 9 but after rewatching I need to increase it to 10 and add it to my all time favorites.
The only thing I would see as a drawback is frequent advertising, but it is reasonable as the production must have been pretty expensive. Also - a tiny spoiler - no Italian, plus such a picky eater, would enjoy an instant coffee XD