I'll be upgrading to the 6S+ from the 6. A bit bummed that Apple gives us a 16GB phone for over $750, but I guess that's just the way it goes. Good luck doing anything on the new phones with a 16GB version lol.
I'm holding off until I know on RAM as well, if some rumours suggesting the 6s+ is the only one to get 2GB of RAM then I'll probably go for that, if they both have 2GB of RAM then I'm definitely going from my 6 to the 6s. Kind of disappointed however that they didn't go for the new darker Space Grey in the iPod Touch, as I HATE it on my 6 because it looks silver, but I don't get along well with the white bezels on the other options so no choice!
Not until the smaller phone has optical image stabilization. Why come up with a better camera and not include it in both phones? I'm not going to own a phablet because the camera is a bit better.
No, I decided against it, especially with rumors already inkling about the 7.
I like the spec boosts but it still needs something more for me to jump from my 6, which is not even a year old yet. Phones should last longer than that.