I've been considering moving from my S6 to an iPhone 6 plus. My reasons are different from any of those I've read in here though. I also get the serious lag in using the built in keyboard but that hasn't been a deal breaker for me. The thing that has me contemplating moving to Apple is this, I'm just plain tired of being nothing more than a pair of eyes for Google's advertising!
The firsts purpose of Android, as designed by Google, is an as advertising conduit. To shove advertising at its users. This is how Google makes it's money. They don't make money by selling android to the phone manufacturers, but in fact, made android highly attractive by making it mostly open source so HTC, Samsung, LG etc. can use it freely on their devices. The fact that it is a smartphone OS is how they push their advertising to everyone using it. They gather data on their users like crazy in order to make their advertising "relevant".
Since getting the S6 (on day 1), I've noticed a strong increase on the amount and type of advertising. At first I thought it was probably a rogue app (I download few apps) so I cleared the cache and reset the phone. Well, the advertising onslaught continued. I'm just fed up to my eyeballs with it. I'm not so concerned about the data mining because I have nothing to hide, but, by the same token I wouldn't like the idea of someone peeking through my windows at me while I was at home watching TV, nothing to hide, but I prize my privacy for the simple reason that I have a right to it.
I know there will be few (if any) who will likely agree with me in this forum and in this thread, but these are my thoughts and even though I've used android as an OS almost since the beginning of android, I am now seriously giving thought to jumping ship. It's a hard choice after all this time so I'm in no hurry, but every time an ad jumps up in my face on my S6 I seem to nudge a little closer to making the switch.