Apple (NASDAQ:AAPL) is set to unveil its next-generation trio of smartphones on Sept. 12 -- that is, if you believe the rumor mill. The most exciting of the bunch is expected to be the premium model, which should represent a big redesign compared to the current iPhone 7 and iPhone 7 Plus phones.

In this column, I'd like to go over three of the things that I'm most excited to see in this year's upcoming premium iPhone.

Apple's iPhone 7 and iPhone 7 Plus in red.

Image source: Apple.

OLED display

One factor that I really care about in a smartphone is the quality of the display. After all, the screen is quite literally the thing I look at whenever I  use the device, so the beauty of the pixels is of utmost importance to me.

My current iPhone 7 Plus has a gorgeous display. It's highly color accurate, it has good contrast -- for a liquid crystal display (LCD) anyway -- and it's quite bright.

But, done right, an OLED-based display can deliver big image quality improvements over even a top-tier LCD.

Per the rumor mill, the premium iPhone model will have an OLED-based display.

I'm especially looking forward to the inky black levels that an OLED display can provide. Since the color black on an OLED display is represented by the pixels quite literally shutting off and not emitting any light, black on an OLED display looks truly black.

This will be great for when I'm watching television shows (I do most of my show viewing these days on my iPhone and my iPad), and viewing websites with darker color schemes.

ProMotion display

Another feature I'm also really looking forward to -- should it make it onto the premium iPhone -- is a ProMotion display, which is just Apple-speak for a display that updates its contents at a rate of 120 times per second. Current iPhone displays update at just 60 times per second.

The practical impact of this technology is that it makes everything done on a device that incorporates it feel much smoother.

Apple first introduced ProMotion displays into its product line with the 10.5-inch and 12.9-inch iPad Pro tablets, which it unveiled at its annual Worldwide Developers Conference event back in June.

Per Mark Gurman with Bloomberg, Apple "tested" a ProMotion display for the OLED iPhone. Though not all features that Apple tests for each commercial device ultimately make it into the final version, I am crossing my fingers for this one, because it really is a game changer. (If you don't believe me, go to an Apple Store and test out a new iPad Pro; it'll make any mobile device you currently own feel downright choppy.)

A11 Fusion chip

It's no secret that I'm a chip geek. I love new chip technology, and am always highly impressed with the capabilities that Apple's A-series processors deliver, year after year.

I'm hoping that this year will be no different.

Thanks to the move to a new 10nm manufacturing technology, as well as the continued ingenuity of Apple's top-tier chip development teams, I hope to see massive improvements in CPU, graphics, imaging, and display capabilities from the A11 Fusion chip, which will power the premium iPhone (as well as the two standard models).

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.