I've had the iPhone 7 32 GB Matte Black after having a 6s for six months (gave it to my wife so she could upgrade from 6 due to issues with it), so moving from a 6s to a 7 here and so far I've been impressed. First the look, this matte black is just gorgeous. I've got no case on it, and with a black wallpaper this thing just looks so sleek and sharp.
In terms of speed, this thing snaps. With iOS 10 I've had zero trouble doing anything in terms of apps, multitasking, video playback, you name it. The 6s was no slouch though, and moving from a 6s it isn't light years ahead. I think with more apps coming out in the future that would take full advantage of the A10 would further put it ahead of the 6s but for now the difference is not drastic. If you upgrade to the 7 from a 6 or below it, its worth it on processor alone.
I really like the new home button. The feel of the button feels natural now and I've had no problems adjusting to it from the 6s. I love the taptic engine and that may have a large part to do with it, because now when you are using the software and doing things like dropping down the notifications from above, you can feel the slight vibration when it hits the bottom of the screen. Doing other little simple things throughout the software has integrated the taptic engine and I love that you can now feel when you do those things, I think it works very well.
I now have no fear of taking this outside when it rains which is awesome. I can take photos in the rain if I want; I took one the other day with it sprinkling out and had no issues whatsoever. The water resistant/dust resistant feature is a BIG draw for me and now when I go to the pool at the gym I can actually take this with me and not have to worry about it potentially getting wet. When my wife upgrades her 6s, this feature alone will be more than worth it as she works from home and uses the phone a lot.
And the headphone jack? Not missed; I use a Bluetooth headset when I go jogging and when I need to use wired ones I just use the dongle Apple provided and honestly, I don't even notice it. To carry it around isn't a big deal for me since its so small and you can even leave it attached to the headphones if you don't want to risk losing it. My wife also wanted the 6s instead because she hasn't found a Bluetooth headset that works for her so in the meantime she still has the jack in the 6s but in the future hopefully she finds a pair she likes.
So far, I'm loving the iPhone 7 and have no complaints yet.