Report Server Windows service account

Someone posted a similar question a while ago, but I didn't see any reply.
Now I'm running into the same issue, and hopefully someone knows the
definitive answer this time.
In rssetup.chm, Microsoft recommends using Local System to run the
ReportServer service for the following reason:
"If you use a domain user account (even one that has local administrator
privileges), it will limit your choices on how to configure a data source
connection for a report as well as introduce new configuration steps that
are not otherwise required. Specifically, you cannot use prompted or stored
Windows credentials to connect to external data sources. Additionally, you
must create a special user account to support unattended report processing."
However, in readme_en.htm, Microsoft says that you must use a domain
account. Here's an excerpt from the readme file:
"1.10 Domain user account requirement for subscriptions and ReportServer
Windows service running under Windows 2000 or Windows XP
If the ReportServer Windows service is running under Windows 2000 or Windows
XP, you must configure the service to run under a domain account. If you use
an account that does not have sufficient domain permissions, subscription
delivery will fail when the report server attempts to deliver reports to
domain user accounts. The following error occurs when report delivery fails
due to authorization and domain access issues: Failure sending mail: The
Report Server has encountered a configuration error."
I guess since readme comes after the setup.chm, the formers supercedes the
latter. However, I have been running the service using Local System and have
not run into any problems so far. Now, we need to settle on a standard
regarding the service account. But I'm not sure which recommendation to
follow.
LinchiI ran into the same thing... no problems until I tried to use the file
share subscription instead of email. Even specifying a valid domain
account in the subscription config didn't help.
With a domain account I didn't have that problem (though it took me
awhile to discver that backing up and restoring the encryption key is
required when changing the service account).