Yes, I tried using it but ended up returning it because it didn't work for multiple 6990s.  It will fit two 6970s and a single 6990 in the middle, but the case gets really cramped and becomes a hassle for cable management.  I was able to run this case successfully for about 1 week, and it was pretty cool looking while it runs.  The big fan on top has clear blades that light up and change colors.  There's 3 LED lights pointed at the top fan.  It also provides excellent air flow to all the components.  If you're looking for a cool looking case with aesthetic appeal, it's worth it.  For serious mining though, not so much.