[Yaffs] YAFFS on NOR

Hi,
Our use of YAFFS2 will initially be on a NOR-based system, not running
Linux.
I've read (on this list and on the yaffs site) that YAFFS2 works with NOR
flash as well as NAND. Since NOR is quite different than NAND, I'd be
interested to know how common YAFFS-on-NOR is and what the pitfalls are
(if any).

For example, I did read somewhere that it is substantially slower to
write files,
so it would be nice to know how much slower. Also, are things like
wear-leveling,
garbage-collection and power-hit safety tested in a NOR based environment?

Thanks in advance for any thoughts on this.
Ed