Alternative cluster location

MY version 7.3 setup uses the default cluster data directory of

/var/lib/pgsql/data

and I'm aware that one suggested alternative is

/usr/local/pgsql/data

In my reading of server setup configuration and and drive partitioning,
though, I came to believe that the partition mounted at /var should be
used for "temporary" data, such as mail spool files and log files, and
typically, that that partition doesn't need to be large (in comparision,
for instance, to other partitions such as that mounted at /usr, which is
large to accomodate installation of applications, or /home, which is
large because I typically define that partition to "remainder of disk
space").

So I've been thinking that the /var/lib/pgsql/data default cluster data
directory was an odd choice, since a database, which while definitely
subject to lots of change (which favors /var...), is likely neither
temporary nor small (which argues for somewhere else, I think).

But since I know enough to know that I don't really know enough, and that
the team that decided on the /var... or /usr... default directory
probably did so with good reason, I'm compelled to ask what do some of
you think about the idea of creating a "home" directory for postgres on
the partition mounted at /home, and using, say, /home/postgres/pgsql/data
as the cluster data directory (or with specific reference to the thread I
started about "conservation of OIDS, I would use three cluster data
directories: /home/postgres/pgsql/data/prod,
/home/postgres/pgsql/data/qat,and /home/postgres/pgsql/data/dev )?

What would be the downside to this approach?

~Berend Tober