Ive used my 6s since release. But the battery started to finally give out. So instead of investing $100 to replace it, I just upgraded to the 11 with no money down from Tmobile. Also I really want a better camera for casual photos. I plan on keeping it though since it served me so well and can always be a backup just in case. Huge upgrade for me. Before the 6s, I upgraded annually.
Pretty much my position. The stated increase in battery life is greater than my current battery life, so it's time to upgrade.