CM; LeeDroid; MIUI and most recently Gingervillian have all offered mediocre power management options. The fact you have to root your phone and install custom firmware to make it work better tells me there is something intrinsically wrong with Android platform. And don't get me started on the fragmentation.
I do not want to have a OS war.
I am giving facts about both operating systems.
In Android, if you want more usablity, you ROOT.
In IOS, if you want more usablity, you JAILBREAK.
(The difference is that ROOT gives you the ability to do anything to your phone so this is for slightly more advanced users, for example you can download an app that, at a tap of the screen can install a whole new version of the operating system, like CM, or make backups of all your apps & data)
Please try not to be so bias, I'm trying to give facts in order to make an informed decision, the choice is ultimately up to the chooser.
If you want an expensive, heavy brick like, small screened, simple and extremely fragile phone that is locked to iTunes, then go Apple iPhone 4, it also has 3 times slower internet, non replacable battery, worse camera & video camera, not customisable at all, has no SD card expansion, Apple is the way for you! An iPhone is like a mother trucking Unicorn!
This works for some people and those people love these limitations, for unknown reasons.
another feature that the SGS2 has over the iPhone 4 that probably hasn't been mentioned is the ability to play 1080p video flawlessly.
If we include the iPhone 4S then heck, why not include the Motorola RAZR Droid and the Galaxy Prime.
http://www.ibtimes.com/articles/207799/20110902/samsung-galaxy-s2-iphone-5-apple-united-states.htm
Sent from my ASUS Transformer, rooted with Revolver ROM, 1.6GHz