I removed the original 1TB hard drive from a new mid-range 2012 Mac Mini and added two 256GB Samsung 830 drives. Following an installation procedure similar to iFixit's for adding a second drive I had only one issue - very slow boot. After resetting the PRAM the new configuration worked fine. The PRAM reset was essential on my 2012 Mac Mini.
I used Carbon Copy Cloner to clone OS X Mountain Lion to the boot SSD drive.