*Shrug* How are you defining efficiency, exactly? Efficiency is getting a specific task or set of tasks or action(s) done with minimal wasteful expenditure.

Carrying a handgun around if all you want is to put bullets into soft human flesh things IS more efficient for that task and that task alone then driving around in an armored car with a mounted missile launcher and machine gun combo. But that armored car is going to do other things, that the handgun simply can't do - like protect you from bullets and fire missiles. At the end of the day, when you need to fire one bullet into one human-flesh thing, the car-mounted machine gun and the handgun will have very similar efficiency - firing pin hits bullet and the gun-powder goes boom.

But then that handgun is very inefficient if you want to use it for any other task, beyond a narrow range of functions.

Similarly, I don't think it's a matter of Maemo being more or less *efficient* then Symbian. It's just that Maemo does more, and thus has more stuff running in the background. Keep it to just the kernel and telephony, and whatever else symbian does, and it'll probably run you about the same energy consumption on the same hardware.

Of course, I'm not an expert, but so I suspect.