I'd like to mention my own few cents about this. I know a lot of the top dawgs here at DroidForums don't believe in task killers and there were many posts where people just kept quoting/linking in almost troll-like fashion anytime someone asked something about task killers. I'm glad many of you believe in that, but if you look at the serious discussion going on Reddit today and some threads on XDA, you will see that the community is still quite split. It's not a definitive YES or NO answer.
Google tells you you don't need one just like Apple told us we don't need multitasking and Microsoft tells us we don't need copy and paste in Windows Phone 7. You know why? Honestly, I do understand how Android is supposed to work. When developers code their apps the proper way and Android is working 100% efficiently, you will see memory allocation at its best. You have to realize that people who have used task killers have admitted that Android's done a better and better job from 2.0 to 2.0.1 to 2.1 and then to 2.2. So this means that Google has already stepped up its game. If they now say you don't need one at 2.2, then does that mean all you troll posters who kept saying you don't need one since the days of 2.0 were wrong? I mean clearly there's been improvement right? So something justifies using it.
It's just like launchers. Remember when Helix first came out? Everyone said "OMG FASTEST THING EVAR." Then 1.4b came out (for those who paid) and people were like ZOMGZOMGZOMG SO MUCH FASTER. Okay? So when people whined that the original was slow compared to the iPhone and others said STFU, what did they say when 1.4b came out? Everyone said "well this new one is so much faster." Then LauncherPro came out. That became the new fastest thing. So what? Helix is like a turtle now compared to LP. Was it wrong to whine back then? Like I said, there's room for improvement.
The same goes with memory management. No one can say Android is flawless. Coupled with the fact that developers aren't flawless either. I know many of you have experienced flawed apps or rogue apps that go on infinite loops. Heck the stock browser has done it to me. Speedtest.net has done it to me with the GPS constantly searching for a location because there's no Exit button and I'm in a large building with no GPS signal indoors. So I drained 30% battery in a mere 15 min or something.
The point I'm trying to make here is that Google wants us to believe that Android should be able to do it all. Just like Apple wants us to believe you don't need TRUE multitasking to get things done. Obviously Apple's OS 3.0 only did half the trick with push notifications which is why iOS 4 adds so much more. And Android sees this from its memory management perspective too. New Android builds are constantly trying to upgrade this. But to say its perfect as it is now and does not need human intervention is ridiculous.
Task killers have their place. Just like overclocking a computer does. You could say 99% of people don't need to overclock their computers. It just wastes power and creates extra heat. You know those typical gamers who just buy "fast" computers and now everything comes with an Easy button for overclocking. Do you really need that for Starcraft II? For someone like me who's a member of XtremeSystems forums where people do some crazy liquid nitrogen setups, I spend days reading boards, talking to people, understanding optimum memory timings and voltages as different sticks of RAM made by different manufacturers, and even different batches have different optimum settings. It takes a long time to nail that out. Yeah, i might not HAVE a legit reason to overclock but its my hobby. I enjoy it. I tend to think the rest of the world who just hits an easy button as its the cool thing to do now has no reason to do it.... on top of the 98% of the world who doesn't even know what overclocking is.
To me, if you're not willing to understand something, yeah there could be a reason why you don't need to do it. But does this mean I should tell gamers who don't raelly understand the art of overclocking NOT to overclock? Does this mean people who don't spend everyday in their garage inside their car shouldn't buy fast cars and nice cars? No. They just aren't getting the full experience of it all, but it doesn't mean people don't benefit.
The same goes with task killers. A newb might get one thinking itll triple battery life or free up CPU cycles. But in truth maybe only memory is being freed up as none of those apps are really consuming CPU cycles. Once in a while he'll catch a rogue app and think that it made a world of difference because without one he might run out of battery in 10 minutes. You're absolutely right when some apps really just load into memory and this is not the same thing as eating CPU cycles. Sometimes task killers use more power than the app loaded in memory does. This is why it takes research and understanding of the OS and apps to figure this out. But a task killer on idle used for manual killing won't eat that much power will it? I'm sure if you just use it once a week to kill a rogue app, it'll use far less power idling than sending and receiving 2-3 text messages will use up. So really, does it hurt?
I'd also like to point out LauncherPro already pushes the limits of Android memory management. There are tweaks and hacks here and there to get the screen to stay persistent so it doesn't need to reload the widgets. This launcher that so many of you embrace as godlike already tweaks with Android memory settings. And here you are saying Google knows best and that Android has already been setup to accommodate every user. No, it's not setup perfectly.
And this is why you can use a task killer. For 99% of us, yeah, Android on its own will be fine, but for those of you who care and know what you're doing, you could see a difference. Just be sure you know WTF you're doing. But the answer isn't "NO DO NOT USE A TASK KILLER THEY ARE USELESS." or "YES OMG IT MAKES MY PHONE FAST 24/7." KNow the drawbacks and benefits before you make a sweeping general statement.