Should I buy an iPhone 5 or Samsung Galaxy S4?

I've had an iPhone 4 for about 2 years now, and it hasn't given me any problems until the power button stopped working a few days ago. I'm eligible for an upgrade and I've been hearing a lot of good things about the new Galaxy phone. However, I'm so accustomed to the iOS software and iMessaging. What are the pros and cons of both phones?

Which should I choose?

Galaxy is better

Nothing is confusing about these TWO phones specs?
There's a SAMSUNG GALAXY between the phones

The only similarity is tariffs and that Apple SERIOUSLY OVERCHARGES for its products http://www.itproportal.com/2012/09/06/8gb-iphone-4s-version-be-introduced-iphone-5-launch/

So just to make the final point it's an S, so a tweak which is NOT more than 3 / 4 changes and hike in price.

1) Everyone recommends the IP5 and NEVER mentions the price. IPhone prices / tariffs on any all networks defy logic and gravity

2) Slick advertising does NOT mention this

THREE as "3" was just too short note merit)
The Samsung Galaxy S II (2)was released in MAY 2011 & has 1.2Ghz Dual Core processor with an 8Mp camera.

18 months later November 2012 Apple puts a 12Ghz Dual Core processor & 8Mp camera in a phone and call it the IP5

4) iPhones play catch up what is on an iPhone came out months before on other makes.Eg the iPhone4 was the FIRST iPhone to have a camera flash yeah 2010.

A total of 9 things are missing as All IPHONES do NOT have BLUETOOTH MEDIA TRANSFER! So NO sharing SGS II 9 MORE, SGS III 9 MORE S IV 9 MORE,

The IP5S released anytime within the next 3 to 4 months it being an S will be a tweak so still Dual Core IMO the IP5S will NOT surpass the BB Z10

The IP5S will in all likely hood remain @ 1.2Ghz DC which is less than that of the LUMIA 820 and Windows 8 phones at 1.5 GHz DC

The people who queued up and missed out on sleep for the launch of the IP4 should have stayed in bed got up and bought a SGS II, painted an Apple logo and announced to the world " this is the future"

Like I said playing catchup means it is new IF all you know is Apple then the IP5 is an upgrade, for many the allure of iPhones has gone as we simply have MUCH BETTER devices.