Many users don’t need 960GB, let alone 1.92TB inside a MacBook Pro.
But some of my consulting clients need such storage on the read, and now it is possible using the 960GB Mercury Electra 3G SSD. That kind of capacity is something simply not possible with the Retina model.
The Electra 960GB is actually a RAID-0 stripe internally, which accounts for its unflappable high performance with both compressible and incompressible data.
Test results from the June 2012 15" Macbook Pro.