I've taken the time this weekend to make a few changes to the CM 690 II Adv case and my temperatures dropped almost 10'C on both my GTX 460 graphics cards and CPU - but it might also be slightly attributed to lower room temperatures.
The i7 CPU @ 2.93GHz never exceeded 55'C and the graphics cards didn't exceed 62'C & 70'C respectively, where my CPU would usually peak at about 69'C and the graphics cards at 70'C and 76'C.
I've moved the top 140mm fan to the bottom, which probably made the biggest difference. I've also removed the bottom HDD cage, since I only have 1 HDD & 1 SSD installed.
I completely redid all the cabling, so now there's a nice & clean air channel from the front top 120mm fan, that I've added with cable ties & double-sided tape, to the CPU.
I did get a lot more respect for the case after I had to work on my church's PC's this weekend & with the new temperatures
The HAF 912 is most likely better than the 690 II due to it being able to take 2x 200mm fans, where the 690 II can only take 140mm fans.
You can get the HAF 912 (Windowed) version at Prophecy Shop for pretty much the same as what the non-windowed version goes for at Rebeltech:
http://www.prophecy.co.za/coolermaster-advanced-rc912akwn1-chassis-with-window-p-86924.html