Curtis Baldwin :
is there any real difference between the three cases?
i've had my hands on all 3 cases. i personally own the antec 902, it's heavy and well made, solid like a tank. so you're getting a nice case. that said installation is a bit of a chore, cable management isn't great there isn't room for a 240mm water rad (though you should be able to install a 120mm one just fine). overall i love the performance i get out of it. it moves air faster and better then any case i've ever owned, it moves the air so well inside the case, that the mesh on the exhaust vents is HOTTER then the air inside the case. that's freaking efficient airflow. If you plan to aggressively overclock with an AIR powered cooling tower, this is a great case for you, right up there with one of the silverstone raven towers (which are much more expensive). The negatives are it's very user unfriendly for servicing and installation.
The HAF 912 on the other hand, is also a fairly nicely vented case. In my experience i never saw ambient air temps get warmer then the room, which is about all you can ask for from a case. it's not quite as "aggressively" cooled as the antec, but it does a nice job. it's pretty user friendly to install and service, it's also much lighter then the antec, and feels flimsier as it's about the same size. it's a nice case and a nice low priced option to look at.
The corsair 300r is the smallest case i mentioned, though it's clearly designed for any type of closed loop water rad you might want to use. it's also the most user friendly of the three... and probably (IMHO) looks the most "high end" with a subdued classy look and finish, and a polished inside. personally if i wanted to build a system with a high level of both looks and function, this would be my case. That said it isn't really quite in the class of the HAF 912 or Antec 902 for airflow. But just because it's not best in class doesn't mean it's not quite good at moving and venting air, because it's very good at both..