what is the diffrence

[Linkster]

Halfdeck - that link that you posted is checking the stored text file that Google has for that url to get posted in the toolbar PR display - what makes that any different than just using the toolbar other than not putting cookies on ones own computer? That datacenter is one of the standard BD servers.
That xml is how Google transmits the text file to the toolbar and that has been around since 2002 and works as long as you know the checksum for your urls - it shouldnt be a problem using unless you are doing any auto queries.
Its interesting that they still serve the xml as they replaced that with a little text file some time back (a few years ago) to transmit the PR to the toolbar