Got the bag for my Samsung Series 5 Ultrabook bought 13.3 inches, and it fits perfectly! (Even with inserted mini USB sticks left and right) offers good protection and looks classy + upbeat.
The only small negative point: if you use the bag as a soft pad for the Ultrabook, his feet press such from the material that it takes up to 2 days until it bumps are gone - so do not do better ...