I would have to say its a toss-up. I like the modular drive cage but. I also like the dust reduction system... My coumputer always seems to be sucking up dust... Maybe ill have to move to liquid cooling if I win this.
I would have to say the top slide cover to cover or expose the top mounted fans. I currently have a HAF 922 case and have had a few close calls with things dropping into the top fan which would in turn give me a VERYYY bad day!
Dust filters, without a doubt. I live in Texas, have zero carpet in the house, wife sweeps and mops every day and we STILL have dust problems. I clean the filters on my PC once a month and wish the wife had filters on hers.