I've used it for a while and can recommend to install it.
As a result of detailed information from customers who used the Customer Error Reporting Utility, a number of problems were identified and fixed in the following areas:
AutoCAD Architecture 2008
- AEC Details
- Drawing Management
- Export to AutoCAD
- External References (Xrefs)
Knowledge Base document: AutoCAD® Architecture 2008 Service Pack 1
PS. If you have the beta version of SP1 you would uninstall it first. Yes, the SP is uninstallable.