I was at the apple store early this morning and I got the chance to play with both. It seems to me that the 6+ sometimes stutters when scrolling long lists in certain apps (you can see this clearly in the Notability app). It looks like it is pushing very hard to get those 400 plus pixels to perform. This was not seen in the 6 where everything was fluid and stutter-free. Now, it may be due to ios 8, but I could see a difference. I haven't be able to get either phone, but I am thinking that the 5.5 display will be really nice when the S version comes out next year. Just my 2 cents.