Originally Posted by sax1981
Starting in Froyo, Android has become more efficient at it's own native memory management than past versions and Gingerbread continued that improvement. What this means is that if Android starts running low on RAM, it will start killing things itself and reclaiming/reallocating the memory without the need for a third party app. The other concern about using a TasKiller most people raise is that if you set it to autokill, system apps or other sort of apps that need to be run(such as Facebook widget, other kind of widgets, noLED, et al) will relaunch on their own causing the TasKiller to kill it again... relaunch... kill... relaunch... kill keep your CPU cycles at 100% and draining your battery quicker than it should be.
That being said, I still use a TasKiller on autokill with the screen off simply because I like to (and paid for the app, so dangit, I'm gonna use it! :P). Once you have identified the apps that relaunch upon kill and set TasKiller to ignore them, the battery concern isn't an issue.