AMD Phenom II 555 X2 BE
Dynatron Genius G950
MSI 870A Fuzion
2x2Gb Crucial Ballistix Tracer DDR3-1600
XFX 9600GSO 768M
500Gb Seagate 7200.10
Sony Optiarc 24x DVD+/-RW
Ultra X3 800W
The only issue I ran into was with the power supply installation. The X3 800 is 7½" (190mm) in length, certainly not the longest power supply we've tested but admittedly longer than most standard ATX class units. With the modular connections on the back of the unit there was interference with the 2½" drive cage. Once the cage was removed the power supply fit with no further problem. The X3 800 is an older style unit. All of the 750 watt class we've tested recently have been around 6½" in length, so it's unlikely you'll have the same issue if you use a newer power supply.
Installing the rest of the components into the HAF 912 was a breeze. As I only had one optical and one hard drive to install, I used the top spot in both cages, and the tool-less mounting worked very smoothly. The Dynatron Genius tower cooler is a bit oversized, and as it uses its own mounting system instead of the factory style retention, room to attach it was a bit cramped. There is plenty of space for the video card however, the 9600GSO is an 8½" card and there is 11" between the rear slots and the front bays. If you need more room than that you can always take out the top 3½" drive cage, giving extra clearance for those HD5970 CrossFire installations, while still leaving two 3½" bays available at the bottom.
Let's wrap things up with some final thoughts and conclusion.