I forgot to mention that the SP1 installation decided to hang at the last with "Setting up Personalized Settings for Windows Desktop Update". Took a reboot to get SP1 installation to complete.
Today, we're suddenly working reasonably quickly again, but instead a couple of functionality issues have raised their heads. "Outlook has stopped working" with the solution offered: "problem with the send to bluetooth add-in, do you want to disable it?". It wasn't a problem before, but apparently now it is, but since I have never used this feature from Outlook I disabled it, and that's gone away. The other is that the audio service now fails to start.
Not looking for solutions or suggestions, thanks just ranting!
Apart from that I think that Win 7 is a great OS; I've got XP on another PC that can't be upgraded to Win 7, but I'd never willingly go back to that.