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I own an Antec 1200. The 902 is just a smaller version. It's a great quality case that's (surprisingly) silent with the fans on low, it has good cable management options, etc. The catch is there is no removable mobo tray, and it's definitely not tool-less.
922 - The 902 is quieter, has (arguably) better airflow. The 922 is much more user friendly than the 902, however. It has a mobo tray (or so I've heard) and is tool-less.
CM962a - I really like this case. I would put it on priority over the 902 and the 922. It's very user friendly with a tool free design and has a lot of neat features, like the built in hdd dock, etc.
If you want to move your computer a lot, make sure you get an aluminum case.
To me, if you absolutely NEED a mobo tray and a toolless case, then don't get a 902. If you want the most user friendly one, get the 692 or 922.
All of these cases will fit a 5850.
Cheers.