OK I've been using these apps and all I can say is this: They DO save you battery, simply (as was mentioned earlier) for doing things like switching off the radios etc when theyre not needed. They primarily save you more battery when you're NOT using the phone, in terms of practical usage.
There is no escaping the fact that the screen is a battery sucking whore, and personally what I'd like to know (perhaps another thread is required) is how long of constant screen usage can you get, until your battery is dead as a doornail? Sure, I realise that constantly browsing the web, is different to playing a 3D game, but it would be nice for people to submit some results anyway. As soon as I get the chance, I will disable screen sleep and see how long it takes to drain from a full charge. I think that would be interesting. In other words, is the screen solely responsible for bad battery life? And how much do the other components affect battery life as well? I've heard people blaming a Tegra 3 driver bug for example, saying the CPU is to blame for bad battery life. Things might become a little clearer when more people submit results.
