Eh, I think Samsung did a lot of copying in earlier versions of their phones, but they’ve differentiated themselves enough at this point to be considered more than a knockoff.
In the original lawsuit, Apple had a strong case that a Samsung Galaxy phone could be passed off as a iPhone 3G or something. At think point, I don’t think anyone will confuse a SGS4 with an iPhone 5, neither on the hardware nor the software side. I think that this “lets put every type of gimmicky feature we can think up on this phone” thing is now their mode of differentiation, and it seems to be working pretty well on the sales side of things.
This is something I will never understand about android. It doesn’t matter how quick a new CPU is or how many cores it has, it will always have some lag. My One X lags considerably when swiping from on homescreen to the next, and honestly, it seems silly to think that swiping across a homescreen can max out a CPU or GPU.
And yes, my lumia 800 with it’s paltry single core CPU was stutter-free.