Have bought the cpu i7 5820k and now i need to decide for the motherboard.

The only diffrence i can see so far between these two Msi x99a Raider or Msi x99a sli plus is u have 4 slots for gpu on sli plus.

Any pros and cons ? is anyone using one of theese boards and can u give me a hint on its usefullness ?

thnx