With the SQLite test profile there was not any change in performance across the three Linux file-systems.
The Btrfs file-system improved slightly with the Linux 2.6.39 kernel when it came to running 12 Dbench clients, but the XFS file-system experienced the biggest improvement. Moving over to the Linux 2.6.39 kernel caused nearly a 20% improvement in performance, likely due to the multi-threaded meta data speed-ups. There was no change with EXT4 for this workload.
The Flexible I/O Tester did not spot any EXT4 / Btrfs / XFS performance changes on the Linux 2.6.39 kernel for this SATA disk.