Another year and another 's' update from Apple -- this year everything is different, though. Now it's as if you own an entirely new device due to the increased speed, ignoring the added functionality.
I usually never really rush to grab the 's' revision, but I always end up buying it at some point. Given how all carriers have switched over to their lease programs, or $0 initiatives, I imagine that many will be more inclined to grab the upgrade than they typically have been over past generations. I know that's what swayed me to it, because I couldn't have cared less about 3D Touch but the added RAM and updated processor had my attention.
I'd like to say just as you can expect, it's faster, but it's faster than that. This is definitely not what I had anticipated when I first picked up the phone. I couldn't believe how slow my 6+ felt after using my 6s. It's always funny after a device refresh because the current handset always feels great, just monotonous, up until that point -- it then becomes 'how was I using this?'.
Touch ID is now annoyingly fast, I still haven't adapted to using the power button to check notifications -- instead, I frequently want to throw my phone each time I go to check what's on the display, or even just the time, and my phone is unlocked by the time it goes from pocket to face.
3D Touch isn't really for me, I don't see its purpose. I understand that it's a new technology and that advancements in applications will be made over time; I still don't see where I'll find it to be a utility, primarily because it's an extra step to replace an extra step. I still need to think of what to force touch, then choose the option -- no different than opening the app and tapping the menu item.
Camera is excellent just as you'd expect. I'm seeing better low light performance out of the 6s than the 6, and I expect the 6s+ to be that much better. The higher quality, while marginal is noticeable and appreciated. The front facing camera for 'lonelies' is never used by me, so that spec bump I'll never be able to appreciate. Sample photos are below to see how the images of the 6s step up to the plate. (Yes, I only take photos of food and my dog.)
Battery life surprised me, I was able to get 6-7 hours of screen on time without using reduced power, with a 6s. Still not enough for me to be willing to use the smaller handset but I'm looking forward to my 6s+ arriving to see how it performs. I usually get 10-12 hours screen on time out of my standard 6+ so I see it being no worse than that. This in itself is a feat when you take into account that a Galaxy Note 5 sees roughly 5 hours of screen on time, according to most reviewers. Everyone wants to discuss incredible standby times, but those for me are irrelevant seeing my phone is constantly in use, I don't consider it a real life statistic to determine battery worthiness.
All in all, with the given carrier device models currently on the market for US consumers, I see no reason to not update. If you're abroad, or Canadian, if you never use the 6s/6s+ alongside your current device you won't miss not having it, but the moment you pick it up you'll be ashamed to look back on your 6/6+ again.