iOS and Android have evolved so much, previous differences are being eliminated/blurred, so generic stuff like social networking / web browsing / music on the go / video / etc are pretty much equal. They do have their minor differences, but I don't think it's gonna be make or break in most decisions.

Between the 2, if you want something relatively hassle free, etc, you should stick to iOS.
If you like to tinker, go to Android. If you prefer large screen size and all, go Android as well

Not to say the 2 can't do otherwise, (manage your Android properly and it'll definitely be hassle free, and who knows, next iPhone might finally have a decent size for a touchscreen phone) but those are the core differences imo. Ultimately, both have evolved and are currently mature enough to be able to most functions you'll expect on a smartphone. So don't worry bout "can the device do this and that, etc". It may not be apparent, but both can do most stuff, albeit some might need some tinkering.

And no, doubt S3 will come out in Feb. Samsung has clarified they won't announce S3 in the coming MWC, and they do have a separate event, but that's in March I think. Honestly, by the time it hits the shelves, you're looking at May or June imo.

And on the subject of auto sync, it's not like iCloud, that's something different. Certain apps allow you to sync data in the background, for convinience. e.g. facebook, news readers, twitter, etc. This means in periods, it'll download news feeds, etc. You can of course switch all of this off if you don't like it. Basically synchronizing your phone with whatever service, but automatically done in intervals for you

What I heard was iPhone 5 will be released not that early as expected.

Hmm. Anyway, Android is customization god. Something like Apple, you can't install EVERYTHING but rooting will allow you to do so. Yes in some way, you can consider that managing.

Basically, rooting allows you to access the phone's database instead of just memory. Of course, sometime it wrong move will cause instability etc.

Of course, Android has many custom roms and kernels that you can mix and match to get better battery life, performance etc. Unlike apple, you only got to stick to one.

Well there is definitely pro and con and wish you all the best!

I heard on the radio the other day that the only difference between iPhone 4[S] and iPhone 5 is the screen size. If you don't mind using smaller screen than 4.0 inches, buy the iPhone 4[S] better. Less price and same features