Just to let you know the S5 is renowned for being god awful :p My friend had the S5 mini and hated it, it was really bad :lol: The good news is the S6 is literally the best smartphone on the market :nods:
I switched because after iOS7 my iPhone 5C was just terrible. It lagged horribly, iOS is (still) full of bugs.. ugh, it just defeated the point of owning an Apple (the hardware being less impressive than competitors but the software having polish like no other). The S6 is just a beast, it's incredibly pretty, the 4K screen and 600-and-something PPI, Android is really smooth and everything.. just works. Full of little things that make it so much easier to use.
Also I managed to upgrade my contract from 600 minutes, unlimited texts and 750MB 4G to unlimited everything, 3GB of 4G for almost the same monthly cost, and no price for the phone :D