Postgresql 8.0 or 8.1 vs. latest Red Hat RPM

I'm in the midst of a knock-down-drag-out with a sysadmin (who, somewhat
unfortunately, is also a good friend) over how to administer Postgresql on
some new machines we've got in.

My argument is we should use the latest stable version of Postgres. His
take is we ought to use the latest version provided by Red Hat. (This is
for a set of Red Hat Enterprise boxes.)

Normally, I'd just say do what you want in production, I'll do what I want
in development, and we'll settle the differences in committee. But, since
we've finally got perfectly mirrored hardware, we'd like to see the same in
software.

Any particularly compelling arguments or points would be valuable, either
way.

One point of contention in this argument seems to be the notion that Red Hat
ports security fixes to older versions, even if it has to do this itself. I
don't necessarily believe that this happens. That is, imagine that there's
some fix that makes it into the 8.x branch. For whatever reason, this
doesn't go into 7.x. Red Hat is still using the 7.x branch, so it
undertakes to do this work itself. Does that sort of thing really happen?

Is there a general performance improvement from 7 to 8? What about
reliability improvements?

For how long is the 7.x branch going to be under maintenance and development
(by the community, not be Red Hat)? Is there even a time frame?

Again, any thoughts appreciated.

Thanks,
Colin