The Akasa cools considerably better than the 830, both me and WJA96 have found this.
Thats without the extra fan on the side panel. The Eclipse was consistantly 4 deg lower at load on my 2400xp test system with ti4800 graphics card, the difference is even more if you add a SLI setup.
The Akasa can handle the heat much better than the 830, none of the heat is pushed around the case, its straight in cool, straight out slightly warmer.
Its the right dimensions, with the right fan placement which is the optimal way to cool a ATX spec system.
Unless you mount the 830 with focused flow delta fans I could not imagine a situation where it would produce better temperatures than a comparative noise Eclipse.