The cons and pros of Samsung Galaxy S4?

Right, I'm an Apple User. I'm getting sick of my iPhone4. The battery life charge is just pure embarrassment, I have to charge twice/thrice in a day if I put the brightness on. And keeping my brightness on the lowest is not cool, especially when my friends borrows it and gives it back to me saying that my phone is dead unless I put my brightness up.

I'm not fond of the "no flash support" either. I'm officially done with iPhones, do not recommend me the iPhone5 because let's face it, there's not much improvement there. The phone only became taller, extra new features and there's a BIT improvement for the battery life charge, but that's it.

I was considering the Samsung Galaxy S4. My sister owned the Samsung Galaxy S1 and I really enjoyed the phone, it was fun and the battery charge last long. Like when it was on 15%, it lasted half a day. When it's 15% for iPhone users, that's the signal for us to run and haunt down our charger. And it supports flash, which is a bonus for me because I like to watch things online.

Plus, I heard the camera was excellent and I like big screens also. Yeah, I know the Samsung Galaxy S5 is just around the corner but I haven't got a clue on what it looks like...

So I don't know if I should buy S4 because none of my friends has it so I can't experience it first-hand...