Just followed the instructions to delete the sleep image on my MBA (switched to -0 mode) and now it seems that sleep-mode zaps a lot more battery, wake-up time is faster though. Which sleep mode do you prefer? # 0 - Old style sleep mode, with RAM powered on while sleeping, safe sleep disabled, and super-fast wake. # 1 - Hibernation mode, with RAM contents written to disk, system totally shut down while “sleeping,” and slower wake up, due to reading the contents of RAM off the hard drive. # 3 - The default mode on machines introduced since about fall 2005. RAM is powered on while sleeping, but RAM contents are also written to disk before sleeping. In the event of total power loss, the system enters hibernation mode automatically.