I'd like to say that Android is NOT built perfectly and is not bulletproof. Just because Google's engineers choose to defend its OS to the very bottom doesn't mean anything.
Obviously we know the DROID gets laggy or so when you go below 30 MB of RAM. This can occur sometimes because minfree is set to 32MB by default. This means the system will try to kill apps to maintain 32MB of memory AT LEAST. You could go below and this is where teh system tries to free up some memory. Even 30-ish memory isn't that great. 50MB is where things really get a lot smoother.
Now the arguments state that its wasted real estate... yeah but your system is unresponsive. Do you keep your Windows system loaded down with no free memory? Don't even argue Windows or Linux or whatever. The fact is the system would have to waste CPU cycles to clear up some memory for you to have a responsive OS. And if you have very little memory left, you would have to kill more apps (even if this is done automatically) to make the experience decent.
Now I admit Android does a pretty good job on its own, but you can't say its flawless. Many of us have tweaked MinFree. what if 40 MB works better? Or 50 MB? 60MB? Obviously you don't want some high number like 200MB because the DROID only has 256MB to start with and you wuold be wasting 200MB for system responsiveness. Not only that your home screen would probably never stay cachced and you would have to redraw and a lot of critical apps such as push email would get killed all the time.
So what I'm saying is there's a balance that needs to be found, but to say that Android is perfect and you don't need to tweak a thing with its memory management is utter BS.
If you're unwilling to tweak, that's fine, but to say tweaking is dumb is like saying you accept Apple's judgement and what it imposes on consumers (such as no pron, etc). If so many of us laugh at when Apple makes sweeping judging statements like that as to what it feels is right for the industry and consumers, how come we're so accommodating when Google says one thing about its OS being fine and you don't need to touch it.
If you know what you're doing, that's fine. Use your task killer. If you set it on auto kill every 5 minutes, you're obviously doing it wrong. IF you're killing constantly because you want to see 100MB free then you're doing it wrong. Just make sure you educate yourself about whatever the hell you're doing.