r9 285 crossfire or r9 270x 4gb crossfire?

r9 285 crossfire or r9 270x 4gb crossfire? What is better? 

a single R9 290X

Sapphire Radeon R9 290X 4GB Tri-X Video Card

http://pcpartpicker.com/part/sapphire-video-card-1003612sr

 

I think I will go with the R9 290 vapor X from Sapphire. It's about $100 cheaper.