Been using a DIY Fusion Drive in my Mac Mini for about a year and a half and it's been amazing. Totally reliable and super fast. That said, with SSD prices continuing to drop, I can't see much of a call for Fusion in the future...
That's a link to a 512gb SSD not a 1TbNeither. Get the 1TB 5400 and put one of these in yourself:
Remove all spinners and enjoy the silence.