Both the iPhone 6S and 6S Plus are both tangibly heavier and thicker than their predecessors. If you’ve spent any time handling the older models you will feel the added heft. It’s nothing major — I actually think the extra weight makes the 6S feel more substantial and easier to hold than thewhoops-there-it-goes iPhone 6 — and what you get in return promises to make up for it.That extra weight comes from 3D Touch, which is the highlight feature of the iPhone 6S. 3D Touch makes the iPhone screen pressure-sensitive, literally adding a new layer of interactions and information to iOS.its convinent to buy.!