I was considering this when I was looking for a new case a month ago. What really appealed to me about the 400C was the small size for an ATX case and lack of 5.25" drive bays (what's the point in having those anymore?)
HOWEVER, I ended up going with the its big brother the 600C for a couple of big reasons:
1) The location it sits in the living room is perfectly suited to an inverted case
2) I have 3x 3.5" drives for mass storage and having 2 drive bays was not enough. Yes, the 600C technically only as 2x 3.5" drive sleds, but having the 5.25" bays allowed me to stash an extra harddrive up there using an adaptor. Ironic, I know, considering how I've been searching for a nice case sans 5.25" bays
Funnily enough, the 600C was deficient in one key area: Cable Management. Not that there isn't enough room for all the cables in the back, in fact there is too much. The RM650i that I bought doesn't have enough flexibility with it's PCI power connectors to use all my drives in the locations that were intended for them. I had to throw one of my 2 SSD's up in the other 5.25" drive bay (secured with a couple of screws) just so I could get power to it. This is probably a shortcoming of the RM650i, but I would have thought that a Corsair powersupply would be easy to use in an Corsair case. In reality it was far from.
ANYWAY, This 400C looks like a great little case, and if I had a computer setup at a desk, it would likely be a top 3 candidate for me.
