regarding performance: on a HDD nilfs2 performance was not so great
http://www.phoronix.com/scan.php?pag...s_nilfs2&num=1

My benchmarks http://talk.maemo.org/showthread.php...332#post504332
showed that real fs performance on NAND is not that much better than eMMC:
in the best case (compressed zero data) seq. write was 8 vs. 24 MB/s, seq read
19 vs. 30MB/s but with much higher CPU load for UBIFS.
I expect the differences to become much smaller with typical data.

If eMMC is not much slower, the firmware could copy the whole rootfs to a partition on eMMC at the first boot and from then on forget about NAND and boot from eMMC.
We need some benchmarks for booting from eMMC vs. NAND. Perhaps some of the differences are caused by the watchdog?

@slaapliedje: most boot stuff is in /usr and not in /bin or /sbin
see https://arch.nord.thebc.ch/wiki/inde...sing_Bootchart