Just curious, I use Nova on my Droid Mini but I'm switching to an S5 - in the past I've always hated TouchWiz,and unless it has some new features I doubt I'd stick with it being stock (specifically I love the ability to swipe right and left to have additional docks, especially with a larger phone I think using it one handed will be easier with that option).
Anyway, I know theres no way to disable TouchWiz, but when you use a launcher like Nova do you lose or gain anything as far as performance? Is TW essentially running in the background and then Nova on top of it, or does Nova sorta minimize whatever processing power TW would be taking up?