We have been running the infrastructure update for about 1 month now and have updated several clients as well.

We have only had 1 issue recently with a specific client that had some site templates (stp) uploaded to the site collection gallery and could not create sites from them. In fact, SharePoint just hang there with no message at all.

After looking through the logs, event viewer and every other imaginable place to troubleshoot this issue we decided to recreate the template from an existing site... and voila the problem went away.

So if you are considering upgrading to the infrastructure update, perhaps it would be wise to ensure that you create sites out these templates before the upgrade, then after the upgrade save the sites as templates and upload them to the gallery.

We will keep you posted of any other issues that we may find with the infrastructure update. but so far, so good.