my benchmarks are certainly not representative - if you know some better fs benchmark program let me know. sequential access can at least tell you something about the raw performance of the device.
However, I was surprised that UBIFS/NAND was not dramatically faster than ext3/eMMC
even in best-case scenario for the compressed UBIFS.
Also the CPU usage for UBIFS was 80-100% vs. 10-15% for ext3.
I consider that an important criterium for a mobile device, too.

@shadowjk: of course, HDDs are different, but that it performs so badly even on HDDs is IMHO not a good sign. again, we need more benchmarks...
the seek performance was 1100 vs 3700 on a fresh device but CPU usage was 14% vs 98%
http://talk.maemo.org/showthread.php...332#post504332
not surprising if seeks in a compressed zero-filled file.