I have wanted one of these machines for quite some time, and it finally arrived last week. I was able to connect it a few days ago and all I can say is WOW. It is an incredible machine. Very impressed with the build quality, the easy of expansion, the performance, and the quietness of the machine. It is the 12-Core 3.06 with a 512SSD and a 3x2TB RAID0 array and 2 SuperDrives. I have used many machines over time but this one takes the cake! I also ordered two 27" ACD monitors to connect to the onboard 5870. I primarily do network administration consisting of labs and virtual networks and this machine does not break a sweat. I really wanted to run OS X as the host OS and so far Mountain Lion has been extremely stable. I am very happy with the purchase!