For the first point, it is quite simple that the 830 can achieve much better cooling than almost any case on the market. How do I know that the 830 is better than the 1200? Simple, reviews have pointed out that the 1200 only slightly out performs the 900, and my friend's 830 destroys my Antec 900 and he uses 60 CFM fans, and all my Tricool fans are on high, which is 79 CFM. He also has a system that produce a lot more heat than mine. I get a 29C on average Idle he gets 23c on average Idle. I'm not saying that the 830 destroys the 1200 in cooling performance, but it is pretty simple when you look at it from an unbiased point of view, the 830 DOES has an advantage cooling wise. The second point is simple aerodynamics, the 830 has a positive pressure cooling system, meaning there is more intaking than exhausting of air. The 1200 has a negative pressure cooling system, meaning it has more exhausting than intaking of air. The simple difference is that the negative pressure forces air through all possible openings into the case and most of those openings don't have filters. The positive pressure forces air through all possible openings out of the case. It really is that simple, to me the 830 is the best out of the 3, but the 1200 is a great case for the money. As I said before, it is solely up to the OP at this point, atleast in my opinion. I just wanted to clear the air of some false facts that the 1200 is so much better than the rest, especially in cooling.