I'm hooked on the larger screen since the 6 Plus. So I've lived with the larger phone for over a year. With the 6s Plus I'm getting even better battery life. Honestly in last 14 months I have not had one instance where I ran low on battery.
For the first time since using cell phones, starting with a five pound bag phone, through the flip phone era and razors where I carried two extra batteries, and the whole series of iPhones, and Mophie cases. I no longer think about battery life, nor plan around it. I just use the phone now and plug it in every couple days. Or nightly if I used it heavy.
I will pop on an iPad charger, all I use now, for a few minutes more from habit then need. But in 14 months it has not been a need because I was running low. More like topping my gas tank if I stop for a coffee or see cheap gas price.
Like everyone else I am curious what the new iPhone 7 style will bring. But without seeing it, knowing what is added and deleted it's next to impossible to make any reasonable comment as to thinness, or jack changes. I recall the nashing of teeth, dire threats to abandon the platform when the 30 pin connector gave way to the Lightning port. That died down quickly once the new phones came out and people realized all their griping didn't mean a thing.
It has been stated in articles and interview with Ivy that Apple design teams purposely do not follow, monitor, or concern themselves with customer comments regarding future desires or products. Apple has not ever used focus groups to decide which direction to take designs. Typically changes are introduced with more than the next iteration of product in mind. The Apple design team tells us what we will want in future products. While this may not sit well with some of the users, I defy anyone to make a case that Apple has been incorrect following this process. 93% of high end phone profits argues their business model works quite well.
You can be sure the iPhone 7 is physically in the design teams hands right now and that the 7s, and 8 are also well along design wise. Changes to the iPhone 7 are stepping stones to the iPhone 9 and 10. I have a strong feeling that solid state batteries, continued SoC designs enhancements, targeting a single chip incorporating radios, Sensors, GPS, lack of power consuming L3 memory, etc is all in the works.
The current ear phone jack can't carry higher band width so that might be part of it. Desire to achieve some measure of water tightness may be another. Thinness, well it's pretty obvious that is a major goal, like it or not. I can't see the concern any longer about battery life. Take a poll and see if any macrumor's user is heading into Amazon rain forest, otherwise a power boost is a electrical socket away. If someone wants a fatter phone, like some have said, with more battery life get a battery case.
My opinion is Apple is not listening, and has certain goals set. Regardless of a very small but vocal minority on here you can either accept it or find your own solutions, battery case, extras power cell, or alternate phone. That is one very good option, that there are alternate phone available. However, I see the differentiation between phone being less and less each year. Past features are being eliminated, memory card, replaceable batteries, etc. Phone are becoming more and more alike.