PostgreSQL - case studies

Hello all,
Apologies for the long mail.
I work for a company that is provides solutions mostly on a Java/Oracle
platform. Recently we moved on of our products to PostgreSQL. The main
reason was PostgreSQL's GIS capabilities and the inability of government
departments (especially road/traffic) to spend a lot of money for such
projects. This product is used to record details about accidents and
related analysis (type of road, when/why etc) with maps. Fortunately, even
in India, an accident reporting application does not have to handle many
tps :). So, I can't say PostgreSQL's performance was really tested in
this case.
Later, I tested one screen of one of our products - load testing with
Jmeter. We tried it with Oracle, DB2, PostgreSQL and Ingres, and
PostgreSQL easily out-performed the rest. We tried a transaction mix with
20+ SELECTS, update, delete and a few inserts.
After a really good experience with the database, I subscribed to all
PostgreSQL groups (my previous experience is all-Oracle) and reading these
mails, I realized that many organizations are using plan, 'not customized'
PostgreSQL for databases that handle critical applications. Since there
is no company trying to 'sell' PostgreSQL, many of us are not aware of
such cases.
Could some of you please share some info on such scenarios- where you are
supporting/designing/developing databases that run into at least a few
hundred GBs of data (I know, that is small by todays' standards)?
I went through
http://www.postgresql.org/about/casestudies/
and felt those are a bit old. I am sure PostgreSQL has matured a lot more
from the days when these case studies where posted. I went through the
case studies at EnterpiseDB and similar vendors too. But those are
customized PostgreSQL servers.
I am looking more for a 'first-hand' feedback
Any feedback - a few sentences with the db size, tps, h/w necessary to
support that, and acceptable down-time, type of application etc will be
greatly appreciated.
Our products are not of the blog/social networking type, but more of
on-line reservation type where half an hour down-time can lead to
significant revenue losses for customers.
Thank you,
Jayadevan

DISCLAIMER:

"The information in this e-mail and any attachment is intended only for
the person to whom it is addressed and may contain confidential and/or
privileged material. If you have received this e-mail in error, kindly
contact the sender and destroy all copies of the original communication.
IBS makes no warranty, express or implied, nor guarantees the accuracy,
adequacy or completeness of the information contained in this email or any
attachment and is not liable for any errors, defects, omissions, viruses
or for resultant loss or damage, if any, direct or indirect."