Display won't follow sleep settings, uses disabled screensaver instead
I noticed the same effect in full Yosemite installation: screensaver starts when the computer (macbook air) is put down to sleep. If we add to this the battery "eating" behaviour I observed as well. I have unchecked every item that can use power, icloud and handsoff included, but the system itself needs a lot more energy than Mavericks. The general picture of power management seems to be worse than ever.