This series has everything.

Gangsters, drama, unrequited love, comedy, action. What's not to like?

This show literally had me in a choke hold until it was over, and when it ended my only thought was- Wait, there isn't more?
I wish this show had thirty episodes. I'd keep watching these characters for a good stretch longer.

I really like the world they set up (Who wouldn't like a world made up of impossibly hot gangsters who are all secretly in love with each other?) and both couples sold the romance for me. I even enjoyed the little cameos we got, and I thought they were tasteful and not over done.

That's it. My only critique is that I wish it were longer, because I did feel a little bit like they had to rush all of the flash forward scenes just a bit.