What it's like to use the brand new iPhones Apple just announced today

Apple just unveiled its latest pair of iPhones - the iPhone 6S and 6S Plus.

Both phones are a modest improvement on the two models Apple announced last year, but with some very noticeable tweaks. They'll be for sale starting September 25.

I got a chance to try it after Apple's big event on Wednesday. Here are some first impressions.

3D Touch: Useful, not groundbreaking

The new iPhones come with a feature called 3D Touch, which essentially means that the display is pressure sensitive. It's very similar to the Force Touch technology Apple introduced with the Apple Watch.

On the iPhone, though, it's mostly used for previewing things like websites, photos, and so on.

It works smoothly and naturally in practice - and it makes things a lot quicker. For instance, pressing firmly on the iPhone's clock app icon launches a small submenu. From this tiny submenu, you can create an alarm.

The preview function that works with 3D Touch is pretty useful too. In the Instagram app, for instance, I pressed down on a user's handle to get a preview of the photos they posted most recently. You can also use it to access some shortcuts in the Mail app.

For the most part, 3D Touch felt natural to use. There were a few instances in which I accidentally just long-pressed an app icon rather than hard-pressing it, but it didn't take long to catch on.

It's not a groundbreaking feature, but one that's bound to save you some time here and there.

Live Photos: a nice addition

The other big changes coming to the iPhone have to do with its camera. Although I couldn't get a feel for the image quality in the iPhone 6S 12-megapixel camera in my short demo, I was able to get a closer look at Apple's new Live Photos feature.

When you snap a photo in Live Photos mode, the iPhone 6S captures the moments before and after to create a slight movement. You can tell when your iPhone is in Live Photos mode by looking for the tiny yellow circles that sit at the top of the screen within the camera app.

It's a nice addition, and it makes photos look more lively, especially when you look at them up close.

Look and feel: no change from last year

In terms of aesthetics, there's no noticeable difference between the iPhone 6S and its predecessor. They looks the same, they feel the same, and they weigh about the same.

The main physical difference is the new rose gold color option for the iPhone 6S and 6S Plus. Here's a better look at it:

In general, Apple's new iPhones seem like a worthwhile upgrade. If you've got an older iPhone such as the iPhone 5S, it's going to feel much bigger and more powerful. If you're using it compared to an iPhone 6 or 6 Plus, the changes will be less apparent but still noticeable.