The new BOINC version of the screen saver with the 3d rendered display is great!
...however it fails the one true test of a screen-"saver". The SETI logo in the bottom left is static and will burn into the screen - hence you would need a screen saver for the screen saver.
[NB: I do not use the blank screen option as I need to be able to tell at a quick glance (i.e. at the monitor) which machine(s) is powered up and/or is not locked up]
I run the screensaver just like you do, but I switch off the monitor when I'm not at my desk... This might sound a rather dumb solution to screen burn, but it works!!!