The most notable thing about the iPhone XS Max is the screen — the big, beautiful screen.
First and foremost, the XS Max has an OLED display, which no older iPhones have, save for the iPhone X. Blacks look blacker, whites look whiter, and the whole display is just more gorgeous and immersive than what you're probably used to on an LCD screen.
Besides being a better display, it's going to be much bigger than what you're used to, too. It's the largest display of any iPhone, ever, and goes nearly edge-to-edge (save for the notch at the top, and some thin bezels along all four sides).
2. The size and weight
Beyond having a great big screen, the XS Max has a great big body, too. It's the biggest, heaviest iPhone Apple sells, and also the largest phone it's ever made.
Here are the specs:
Height: 6.20 inches (157.5 mm)
Width: 3.05 inches (77.4 mm)
Depth: 0.30 inch (7.7 mm)
Weight: 7.34 ounces (208 grams)
Compare that to the iPhone 6, which is 5.44 inches by 2.64 inches and weighs just 4.55 ounces, and it's pretty striking. If you're used to your small, lightweight phone, you may be in for a bit of a shock.
3. The camera
When I compared my iPhone 6S to the iPhone 8 Plus last year, I was taken aback by how little difference there was between the two cameras, which were two generations apart. While the 8 Plus won in a few situations, there wasn't enough of an improvement to warrant buying the new device for the camera alone.
One year later, that's no longer the case.
I've been using the XS Max for about a week, and every time I switch back to my own phone, I'm disappointed by how my photos look. The camera isn't as sharp and it doesn't perform half as well in low light, and the colors look dull. Plus, my old phone can't do things like portrait mode on both the front and rear cameras.
It's officially gotten to the point where the 6S (and, I imagine, the phones that came before it) feel outdated, camera-wise.
4. Face ID
For better or for worse, Apple abandoned Touch ID last year when it introduced the iPhone X. Now, we have Face ID instead. And Apple has rolled it out to the iPhone XS and XS Max.
Face ID uses the phone's front camera and built-in facial recognition software to unlock your phone using a quick scan of your face. It works fine, but it doesn't work quite as well as Touch ID, at least in my tests. It's a little slower, it doesn't work in every lighting situation or orientation (I can't get it to work well when I'm lying down, for example) and it tends to be a bit slower than using your fingerprint.
The reason there's no Touch ID on the XS Max is because there's no physical home button, which is where Apple placed the fingerprint sensor on past iPhones.
No home button means you're going to essentially have to re-learn how to use an iPhone when you get your new device. The gestures are completely different, and even things like the control center, the reachability feature, or taking a screenshot are accessed in new ways.
This isn't necessarily a bad thing — the new gestures make using the iPhone a bit more fluid than clicking a physical button — but it will take some getting used to.
6. The design
Let's face it: if you have an older iPhone, you don't exactly feel like you own a premium product anymore.
My 6S has an aluminum body and, while it's nice and lightweight, it doesn't look that nice outside of its case anymore.
But when you get your hands on the iPhone XS Max, it's going to feel like a true upgrade. It's a truly gorgeous device, from the all-glass back to the stainless steel edges. I have the gold version right now, and it's the best-looking phone I think I've ever seen.