BFU,
I put SP2 an a friend's machine (as a favour) and it did cause some grief but in general improved security. Had to take it off however as one of the problems I have found insurmountable - at least for the moment.
After SP2 was installed we noticed that some data files had been disappeared and no amount of searching found them; they were well and truly gone, so back up anything you don't want to loose (I am SURE everone does that anyway, don't they...).
Also there was a strange propensity for some packages to suddenly stop, the video output died and the machine hung-up. Not even Ctr-ALt-DEl would get it back.
Some research and advice (thanks eLiam and Evo) lead me to a known conflict between the Nvidia GeForce MX4000 drivers and SP2. Hopefully there will be another update to these which will let me put SP2 back on but I have not yet found it.
Your call!
VnV