Most people, if not all, are experiencing this. Remember that this animation issue is not happening all the time. If you are using the phone fast like I do, and if your eyes are very observant, then you will see it at some point.
When I had this animation thing, I asked my girlfriend, if she had this same issue, too. She simply said "No, I don't see it on my iPhone." She has also an iPhone 5S like I do. First I thought "S...t ! I have defective faulty phone!"
But when we met, I started using her phone the way I use it, and there it was. I was able to replicate this issue 3 times. Ofcourse it was happening on occasion. I had spend like 10 minutes playing with her phone.
When I showed her this issue, she was like "oh this is nothing, it's not important, I would have never realized it myself."
So some people, unlike us, don't even aware that this issue is there. They don't see it. But it is there. Not all the time, but there.
I am pretty sure about 5 & 5S, beacause I use them both. But I have also heard people using 6 & 6+ as well. But I have never heard about 4Ss, 5Cs or any iPads...
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I don't want to give you more bad news but the upcoming iOS 8.3 will have the same animation issue as well.

(( At least the people who are using the BETA version of 8.3 say the animation issue is still there. It hasn't been fixed yet.
I doubt that it will be fixed with the public version of 8.3 either....
