Hi Damian, basically the PokerSeries cards offer the following features: 

• royalQueen: custom PCB, CoolStream cooler, running at stock speeds. 
• royalKing: custom PCB, CoolStream cooler, factory OC out of the box.
• royalAce: custom multi layer PCB with more powerphases, CoolStream cooler with more heatpipes and bigger heatsink and factory super OC. 
• JokerCard: a limited edition with special features and/ or a specific game bundle.

Note that not all cards come in Queen, King and Ace versions by default.