The 902 adds removable air filters in the front, fan speed controllers to the front and rear fans and uses the extra long screws to attach HDD in their cages. (makes the job MUCH easier then in the 900) However unless your in for the size you can typically get the 1200 on sale for about the same price.
 

huron

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Jun 4, 2007
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I love my original 900, but the improvements of the 902/1200 would be nice. The 1200 has those features as well and would be my choice if I was building again today.