I recently downloaded and installed Windows Vista SP1 RTM. This is not a quick install. The SP1 install took about an hour on an Intel Core 2 Quad Gateway desktop. It had three stages and rebooted several times. You can have the install reboot automatically or configure it for a manual reboot. Do yourself a favor and run the upgrade after work hours. The actual install is painless. I have attached the screen shots.
Figure A. Welcome Screen
One major thing I have noticed is that performance in copying files from one computer to another over a network has drastically increased. I have only been on SP1 24 hours. I will let you know more later. I really like Windows Vista. It is an enjoyable operating system to run.
Figure B. Licensing
Figure C. Configuring how your computer reboots
Figure D. Progress