Postgres and Ingres R3 / SAN

Clustering solutions for PostgreSQL are currently pretty limited.  Slony
could be a good option in the future, but it currently only supports
Master-Slave replication (not true clustering) and in my experience is a
pain to set up and administer.  Bizgres MPP has a lot of promise,
especially for data warehouses, but it currently doesn't have the best
OLTP database performance.

So, I had a couple of questions:
1) I have heard bad things from people on this list regarding SANs - but
is there a better alternative for a high performance database cluster?
(both for redundancy and performance)  I've heard internal storage
touted before, but then you have to do something like master-master
replication to get horizontal scalability and write performance will
suffer.

2) Has anyone on this list had experience using Ingres R3 in a clustered
environment?  I am considering using Ingres R3's built-in clustering
support with a SAN, but am interested to know other people's experiences
before we start toying with this possibility.  Any experience with the
Ingres support from Computer Associates?  Good/bad?

Jeremy