postgresql replication

Hello,

in need to increase reliability of the service (and perhaps eventually
offload main DB server) we are looking to setup replication for the
database server. I found two solutions:

Slony ( http://gborg.postgresql.org/project/slony1/projdisplay.php )
PGCluster ( http://pgfoundry.org/projects/pgcluster )

I found that PgCluster supports multi-muster mode, which we can
benefit from, but it's not required for "backup" which is #1 goal at
the moment.

If anyone used those solutions, compared performance, reliability, etc
- please share your experience / thoughts.

--
Vlad