On the TouchWiz debate:
Its not about all about "features" and what it can do. No one in here is saying that Samsung devices dont do alot. Its about being CONSISTENTLY fast, CONSISTENTLY smooth, cohesive, reliable, clean. Thats why alot of people dont prefer touchwiz devices. My last two TW devices were packed with hella features, but experienced lag (sometimes consistent lag), looked cluttered and incohesive, had bugs, etc. And half of the features didnt even work consistently (most were damn near useless). And I am sure that has been most people that have left Samsung's experience with them. I've even spent time with the Note 3 and Note 4, and neither has been able to deliver close to the speed and consistency that I desire from a device.
Coming from Samsung to my M8, the difference was immediately clear. I dont have to do reboots/battery pulls all the time (i only ever reboot it for software updates). I dont have freezes. EVER. I dont experience lag at all. I dont have to sometimes swipe/tap something two and three times for it to happen. I actually USE most of the features. No i cant do some of the flashy TW stuff on a stock M8, but I know that anything I do ask my device to do, will actually happen instantly. I'm sure most people would rather the features they do use be refined and polished, than to have a bunch of random half-baked features that they will only use once or twice during the life of the device. I rarely even have the desire to flash roms and kernels anymore. I've never had the urge to change the launcher.
It. Just. Works.
It all comes down to preference, but to pretend that people (especially people that have had Samsung devices) dont have valid reasons to prefer other devices is silly. Yes, there have been vast improvements with Samsung's software, but its still just not there yet.
P.S.: (TouchWiz is an entire framework, not just a launcher. Changing the launcher only changes a very small piece of the software.)