Using pre-configured vs building Postgres

Hi all,

I am running custom applications on a Linux platform which essentially have
Perl and Postgres as prerequisites. In the past, we used an arcane Linux
distro which left me with no other option than to build Perl + 50 odd CPAN
modules + Postgres myself. I prefixed the stack under a common path like
this:

/osstack/perl/5.12.1
/osstack/postgresql/9.0.4

Yet, now, we switch to a more modern distro (OpenSuse 12.1), which does
have the RPM for Perl 5.14.2 pre-installed with the option to install more
RPMs such as

perl-DBI-1.616-7.1.3
perl-DBD-Pg-2.18.0-3.1.4
postgresql-9.1.1-3.1.4

Once our custom applications are tested and behave, the idea is to freeze
all prerequisites until we go to a different generation (potentially
different distro altogether in >= 5 years).

Before I try to obtain a handful of CPAN modules which are missing or
'unsupported' in OpenSuse, my question to this admin forum is what pro's
and con's to consider when deciding whether to use a pre-configured
postgresql versus building it ourselves.

Best,
-ar