We set up the SCT on the computers in our school library about a year ago. It was a bit of a pain to set up because the drives had to be repartitioned. Once it was set up we found it to be really useful. We were running an ECDL course using the library machines, so we needed to allow the users to have local admin access to the machines so that they could reconfigure them. The SCT was great because they could do whatever they liked to the machines and it just takes a reboot to get the computers back to their original state.
We use mandatory profiles on our network, so we never had any profile related issues. The only problem we had was with stuff like WSUS and Antivirus updates. We had to turn off disk protection every now and then to update the machines, and remember to turn it off to install new apps. You can use software like beyondexec and batch files to remotely turn on/off the disk protection on a number of PCs at once though...
The SCT in general feels a bit clunky to use. Steady State is looking pretty slick though.
