There were a few bad apples in Medici (the highlight was Matteo Martari as Francesco). I just feel like Sean Bean's character was so one note. Not his fault it was written that way.
Sean Bean has given some of the greatest performances (and my favourite performances) I've ever seen. But he has been in a lot of rubbish, and I feel like he knows when it is rubbish and just does it for the paycheck. I don't blame him.
His performances in Broken, Accused, Lord of the Rings, Essex Boys, Sharpe, Black Death, Game of Thrones, are some of the greatest performances I've ever seen and feel like he was born for those roles.
Other exceptional ones are Troy, GoldenEye, National Treasure, Flightplan, North Country, The Frankenstein Chronicles, Lady Chatterly, The Martian, Red Riding, The Hitcher, The Island (that's all I can think of at the top of my head).
Some very one note roles, either due to his performance and terrible writing/directing include: Curfew, Airborne, Death Race 2, Drone, Any Day, Wicked Blood, Soldiers of Fortune.
I will watch anything he is in because I love Sean Bean, but I don't expect to be blown away when I see something he is in, because very often he is in attached to something that is just not very interesting.
This is all my opinion. I hope I have explained myself well. Sometimes I have a hard time articulating my thoughts.