Difference between Pace/Camerons 3D?

Hi, i'm new on this forum. I was researching the new 3D cameras which were used in Avatar, and I thought the only other films to use the same cameras were Resident Evil and Tron. But after going to the Pace website, it says that so many other films have used the same technology, such as The Final Destination, Journey to the Center of the Earth, and even The Jonas Brothers. http://www.pacehd.com/
On the website, there are different types of 3D systems for various films, e.g. Resident Evil used 3 Fusion 3D systems, but Avatar, Step Up, Tron, and Journey to the Center of the Earth used 4 Fusion 3D systems. There are then other films wihch have used lower systems such as U2 (5 Fusion), Jonas Brothers (7 Fusion) and Hannah Montana (8 Fusion). I don't really understand the difference. I think that the lower you are in number, say 3 or 4 Fusion, the better the technology, but i'm not sure? I'd be interested to know what other people think.
Thanks, Stephen

 

essentially pace and fusion are the same thing. mirror rig systems with sip boxes to control dual lenses and genlock. they are pretty big systems so pace is currently working on ways to reduce it to match the atom rig and new red epic cameras coming this year.