I went from the 5 to 6+, honestly I tried to love the 6+. I kept the 6+ for 5 days and it just was to uncomfortable for me, also, it did not fit in my pocket well. I swapped for the 6, I like it much better, but have been considering swapping for a 5s, but I am going to give the 6 a bit more time.
I have a 6 plus right now and honestly, i'd rather have a 6 than a5S. been there done that and will go to a 6 from a 5S in a heartbeat. don't know why people will go from a 6 to a 5s......