(Pocket-lint) - Since its inception, the notch - that black-out area to the top of many flagship phones where the front-facing camera and sensors hide - has been a divisive smartphone design.

Many want an uninterrupted full-screen experience, yet won't forego that selfie camera. And the hole-punch camera changed all that - sometimes to excess, as dual punch-hole cameras are now a thing too (yes, Samsung Galaxy S10+, we're looking at you) - delivering the front-facing camera into a small circular area within the screen itself. No big notch, no big distraction? That's the theory.

Over the last few years, however, we've seen brands experimenting with other solutions too. From the Xiaomi Mi Mix 3's slider phone mechanism - we take a closer look at that now-defunct concept here - to Vivo's full dual-screen approach in the NEX Dual Display, plus now there's talk of the under-display camera seeing an end to the punch-hole's reign.

The upsides

There's no unsightly notch

The most obvious benefit of a hole-punch solution is that it's far smaller than a notch, thus doesn't get in the way of your viewing experience overall.

The camera is placed in an area where the default software-derived blackout strip occurs, so for many apps and much of the software experience, it's hidden from view by default.

Full-screen really means full-screen

Many apps can be designated as full-screen - and that really does mean full screen. Apps can extend beyond the hole-punch to the outer edge of the display, for full immersion, especially on 6.4-inch screen size.

It puts the camera in a good place - no slider/second screen required

With a slider phone, such as the Honor Magic 2, the camera pops-up by pulling the upper screen portion down. While that sounds great, it means various dust and debris can get into the area where the camera is hidden. With the hole-punch solution that's no such issue, which is why we don't expect to see any more slider-phone launches.

The downsides

It's a potential distraction

One of the most obvious downsides is how apparent the hole-punch can be when an app goes full-screen. After all, it's a totally black area, which really shows up on a bright screen. That'll see your eyes dart towards it.

It can get in the way of operation

The other potential issue is that the hole-punch area can hide specifics within an app. One example we've found is video adverts that have the close 'x' positioned almost exactly where the front camera is - which makes hitting it to close the ad a little trickier than it could be. It's not a common issue though.

Furthermore not all apps have to run in full-screen mode - it's possible to designate per-app whether you want a black-out strip (notch style, we suppose) to contain the app within a given space.

The future?

So is the punch-hole here to stay? Well, it's ultimately seen an end to slider-phone designs, and looks to be the current norm.

But, as pointed out above, technology is always evolving - and wite phones such as the ZTE Axon 20 5G already delivering under-display solutions to market, that, we suspect, is the next step that will see the punch-hole design eventually be a thing of the past.

Writing by Mike Lowe.