Is the Raven 90 degree motherboard layout patented? That seems like a great orientation for air cooling.
I really like the the rotated design for a roomy uATX case, it is a very good candidate design IMO. I doubt it really makes a big difference for air-cooling performance (even if Silverstone claims it does). The chimney effect is very minimal in such a short chimney.It does have some very cosmetic advantages however.
Basically by flipping the airflow vents from being front&bottom ---> back to bottom&back ---> top you gain improved cleanliness (word?) on all sides.
- The front facia can be made totally clean as it needs no vents.
- The back can be made very clean as it needs no wiring.
- The top can be made very clean by having a panel cover the wiring (similar to Silverstones cases). Additionally I think there is room to innovate here by having built-in cable routing clips/channel at the top to bundle up all the cables. The result is that the cables coming out at the back is neatly organized.
The big disadvantage is that the case needs quite a bit more height to accomodate for the cables. This is somewhat offset by not having a cable mess on the back that takes up room.