Very happy with mine. I upgraded from a 6S.
Design:
Yes, it's a familiar design, but it's the best designed phone on the market IMO. The body has more metal than any other phone. The buttons, speaker grills and sim card tray are all metal. The 7 looks like a single block of aluminum.
Performance:
I noticed that it's a little bit smoother and quicker to launch. Not groundbreaking from the 6S, but definitely faster than the 6.
Camera:
Daylight shots are comparable, but if you pixel peep, the 7 has less noise. Low light is where you'll see a big difference. The 7 is quite a bit better than the 6S
Battery:
My experience is in line with Apple's claims. 2hrs more battery life than the 6S.
Water/Dust resistance:
Nice to have. I can't tell that it's working because I'm not willing to test it.
Home button:
After using my 7 since launch, the 6S home button feels like a piece of junk. Haptic feedback from the UI is also incredible. I'm always impressed at how fast the taptic engine can ramp up and down.
Speakers:
I found myself cupping my phone way less or not at all.
Screen:
You won't be able to notice much a difference here. The 6S seems more blue and the 7 seems warmer. I did notice the increased brightness and less reflectance in broad daylight.
Issues:
My phone does hiss, but I can't hear it unless the room is quiet and I put my ear up against my phone. At this time, I don't feel the need to return it.