I currently have the iPhone 6 Plus 128 GB. Which I love. I'm wanting to know if I should upgrade to the 6S plus. What's the benefits??? Where's the best place to sale my 6 plus if I do upgrade??? I'm really loving the camera and the speed of the 6S plus. I've went to Apple Store app and almost ordered 3 times but every time I back out. You guys and gals input is much needed and would be great fully appreciated.