I just saw realworld benchmarks from anandtech, and the hybrid drive will be worlds faster than the 5400rpm drives I'm used to (a light user, 13", not a gamer). Just ordered a 500GB XT from newegg, and going to return the Intel X25-M. Thanks guys for the advice anyways.
I save the hassle of invalidating apple warranty and ripping out the SuperDrive, although I was looking forward to the process. This should be simpler 🙂