Not Comparing Apples to Oranges
I am now stuck in the Apple infrastructure (for better or for worse) with my Macbook Pro, iPad and now my iPhone 5S. So I am only qualified to discuss my opinion on they new iphones compared to my iPhone. Now with that disclaimer out of the way time to talk about some phones.
4.7 and 5.5 Inch Phones
I have not held either in my hand but I have held a few of my friends phones which are around 5-inches and they feel pretty big to me. The one nice thing about these phones is that they have made them thinner. With my iPhone 5S being 7.6mm, the 6 being 6.9mm, and the 6 Plus being 7.1mm.
Bigger Sizes = Bigger Features
The bigger phones give us even bigger batteries and longer battery life. Hopefully this will make a bunch of people happy. I am not a heavy phone user but I can quickly chip away at my battery life while waiting for an appointment. I had a plane delayed for 4 hours and I managed to kill my battery life very quickly by playing Catan and listening to podcasts. Sometimes I do wish I had a better battery in my phone but in the last year of having it I can count those times on one hand.
The new A8 processor and better LTE where expected whether or not they made the phones bigger.
Also the new 128GB versions are awesome and at this time only available because of the increased phone size. Sadly no expansion slots but that will never happen. I own a 64GB 5S and only using about 34GB on it. I also have all my music on itunes match or else my phone would be full :-p.
I have never really cared about phone resolution, just as long as it looks nice. People have told me my phone's resolution sucks but I can't see the pixels so I'm happy.