Soft Updates/FFS and Postgresql

Hi all!

Tried searching the web for the answer to this, no real luck. I was
wondering what the current filesystem people would recommend for
Postgresql on an OpenBSD box? I assume it would be FFS, but would the
community agree or disagree on the use of Soft Updates as well? My
belief is that the Soft Updates option is not a good choice due to
the possibility of corrupting the database on a crash. However, I cannot
find a discussion of this with respect to databases one way or the other.

As a side issue, what is the consensus regarding the best open-source
operating system to use for a strictly database server running Postgresql?
Are Linux/FreeBSD/OpenBSD/etc all reasonably close to one another, or
are there configurations that really fly when dealing with large
databases with lots of inserts/selects?

Regards!
Ed