i dont use a task killer and i am experiencing exceptional battery life. however i have not tried using a task killer as of yet. ill be sure to try one in the future.
well saidAutokiller is great but only if used properly. If you set it too high then you will lose performance since apps will keep restarting. To prevent that you need to disable some signal handlers using Autostarts (be careful). That can really get rid of a bunch of useless junk and you'll really see the difference. You should only disable signal handlers if you're comfortable and know what you're doing because you can easily break apps (many depend on signals).
Otherwise, just take the time to tweak the minfree settings so that the stuff that likes to stay open doesn't get killed. You'll still see a boost though since it will get rid of performance and memory hogs like the stock browser and games that don't close.
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