The fact that Apple is still selling the iPhone 6s, a two-year-old phone, is a testament of how good the iPhone 6s is.
Usually, Apple only offers the previous-generation iPhone when it announces a new model.
But if you compare the specs of the iPhone 8 or iPhone X on Apple's website, you'll notice that the phones look pretty similar. You'll be telling yourself: "Yep, the iPhone 6s has this, and that, and that."
The main differences are the chips that dictate performance and certain features, as well as a few incremental improvements to things like the display and camera. These are hugely important factors when deciding which iPhone to buy, but the iPhone 6s is still a top contender, especially for its new price starting at $450.
It should go without saying that Apple's older iPhones are going to be cheaper than their new ones.
The new iPhone 8 phones only come in silver, gold, and space gray. The new iPhone X only comes in silver and space gray.
The iPhone 6s and iPhone 6s Plus come in silver, gold, space gray, as well as rose gold. You can't get an iPhone 8 or iPhone X in rose gold.
If you value design above everything else, the iPhone X would be the iPhone of choice. It's the freshest iPhone design since the iPhone 6 was released in 2014, and it looks downright gorgeous. But the iPhone 6s has an excellent design — and you'll find comfort in knowing that the iPhone 6s and iPhone 6s Plus look nearly identical to the new iPhone 8 models. Both the iPhone 6s and iPhone 8 have the same bezels around the display, same overall shape, and their screens are the same size and same resolution.