I love it - faster processor, better display, better camera, better battery, more storage, etc. and people think it is the same phone as last year I'm sorry I'm weird I care about what a phone does and how it does it and not what it looks like (within reason). I don't care what the icons look like, I care about the screen and not what lines are on the back.
I don't want a bigger phone - today's doesn't fit that well in my pocket. App developers are more important than much of what people complain about
The people saying this are mostly those who have last year's model.
Processor: it is indeed faster. But real world use doesn't seem effected. I've watched a few videos in YouTube comparing and I have done comparisons myself. Things are uploading at exactly the same rate. The performance just isn't actually better. This is more a testament to how good last year's phones are. And of course ios10.
Better display: the color accuracy is better and apparently its better outdoors. In real world tests I can't tell the difference outdoors. As far as color accuracy, I won't fight it. But it doesn't seem to vastly change the way in viewing content, photos, etc. moving forward is always great. But remember. People are talking about being given a reason to upgrade.
Battery: we get another hour out of it. Always a plus to have more battery. But again, we are talking about a reason to upgrade here.
More storage: I suppose there is a subset of people that couldn't live with 128gb and needed to upgrade to 256. It's also nice we finally have a 32gb base model. These are changes I expect to see moving forward and welcome.
Camera: I only have a 7 to compare (no plus) but the photos aren't generally distinguishable. I think a lot of folks just point and shoot. The camera could very well be miles ahead in the right hands. The issue is most of us don't have the right hands. We just use the camera we have. This relates a little bit to the processor statements I made. It's great that it's much better on paper. But if I can't see the difference in practice, how much better is it, really?
At the end of the day I don't think most mean to imply the phone is literally the same as a 6s. They're just not seeing it worth dropping another $650+ this year. I can't really blame them. It's the first year I didn't upgrade (though my wife did), and despite having a bit of envy because she has the new shiny phone (I got the new Watch, which feels good lol) I can't say I feel like I'm missing out.
Of course there are those who come here and say the iPhone is always just a tiny upgrade milking the consumer. I don't agree with that. I do think that this is the smallest upgrade I've seen in a while in terms of actual tangible benefits (or lack therof) I would receive. If I had an iPhone 6 to trade in to my carrier to get thenohone effectively free after installments, you bet I'd be hopping on board though.