When i transfer files from my ubuntu-box
- to the internal flash it's about 7.1 Mb/s (speed when i upgrade the firmware)
- to the internal SD it's about 2.6 Mb/s (speed when i copy a lot of ~8mb mp3 files)

Moving files from card => card or from flash => card is about the same 2.6 Mb/s

So the internal flash should be faster ?