What if I told you that not only does it NOT have bad cooling--but it out performs the Corsair Obsidian 800D, the Coolermaster HAF 932, and at idle, maintains an ambient temperature of only 1 degree warmer than the Silverstone Fortress. The break down is as follows:
Ambient temperatures:
Thermaltake Level 10 - ambient room temperature 21.5°C
Corsair Obsidian Series 800D - ambient room temperature 25.3°C
Cooler Master HAF 932 - ambient room temperature 25.3°C
SilverStone Fortress - ambient room temperature 21.3°C
15mins @ Idle:
Thermaltake Level 10 - 23.4C
Corsair Obsidian 800D - 26.1
HAF 932 - 26.1
Silverstone Fortress - 22.4
Stress testing with three instances of Prime95 along with 3DMark06 at 1,920x1,200 4xAA 16xAF--temps after 1 minute:
Level 10 - 23.4C
Obsidian 800D - 26.4
HAF 932 - 27.0
Fortress - 22.7
After one hour of the same load:
Level 10 - 24.6C ---CPU temp was 62.0C--GPU was 69.0
Obsidian 800D - 29.1---CPU was 63.0--GPU was 75.0
HAF 932 - 27.6---CPU was 61.0--GPU was 71.0
Fortress - 23.8---CPU was 57.0--GPU was 70.0
The Level 10 was found to be the quietest of the bunch, while in some areas the Fortress was obviously the better choice. All testing was done with stock coolers, fans, etc.
A little liquid cooling or even some good high end fans and you're golden. The point is not that the Level 10 is the best case ever--it's just been proven to be otherwise--just that it does have better cooling than a great deal of cases out there, believe it or not.
Is it worth the $850 price tag? HELL NO.
Although I can say that after having my hands on it I can say it's a very thoughtfully designed case. Extreme consideration was given to all the elements of this case, with the exception of one---The fan in the main housing with the motherboard and whatnot doesn't move a lot of air. It's very, very quiet but there are better fans out there that move more than 65-70 CFM while maintaining a 17-19dB rating.
This may not be one of the BEST cases out there, but should they decide to crank the price down to maybe $235-$300, it would be a very nice piece.