I have been using a Mac Mini 2012 with a 240GB Mercury SSD and the OEM 1TB Hitachi hard drive for about 6 months. I just replaced the Hitachi with a Toshiba Aquarius 1.5TB hard drive, made a 1.74TB Fusion volume, and am currently installing OS X 10.8.4 on it. Creating the fusion drive was a bit of a pain - I had to reinitialize the SSD in a USB2 enclosure because I couldn't break the Fusion drive during the first attempt at reinstalling Mountain Lion. This required re-disassembly of the Mini, so if you do this make sure you reinitialize the SSD in advance. Here are the things to look out for. Back up your Mini's hard drive (Fusion volume) before you start. I had a Time Machine copy and a clone made with Carbon Copy Cloner Follow the Data Doubler video from OWC The Toshiba must go in the Data Doubler; the SSD must go in the OEM hard drive bay; otherwise they will not fit The two screws on the outer edge of the Data Doubler need to be left out, otherwise the Toshiba bumps the chassis surface and you cannot install the SSD on top of it. The drive is held to the Data Doubler by only two screws Once you have the Toshiba drive in, insert the logic board most of the way; however, you have to slide the SSD in place before you seat the logic board completely inside the Mini The fitting of the two drives is pretty tight - the Toshiba is a 12.5mm drive. Take your time in reseating the cowl because it will help secure the SATA connectors As usual, beware of the IR connector so that you do not break it! Create the Fusion drive as described by OWC with the current 10.8.4 installer My install is proceeding with Migration Assistant. It should be done in about 6 hours!