The iPhone Duo has been in reviewers' hands for at least a week, and early reviews are starting to trickle out. I read and watched reviews from multiple sites, including the Tom's Guide iPhone Duo review, to find out what consistent flaws critics found in Apple's first foldable.
Overall, the reviews are quite positive, with a common refrain being that the iPhone Duo is an early adopter device. This means that there are some initial growing pains but with plenty of room for Apple to grow.
Most of the complaints come down to hardware issues, both what's missing (Face ID) and how it feels to use the Duo. One consistent flaw is software-based, but that might be fixed before most people get their foldable iPhones in a couple of months.
Let's dig into the seven most common flaws in the iPhone Duo.
The price
Bringing it back to the early adopter tone, price is mentioned in every review I looked at, but it's not listed as a major concern. Most reviewers acknowledge that the $2,000+ price tag is high (higher than the Galaxy Z Fold 8 by $100).
However, compared to other foldables, the iPhone Duo appears right in line pricewise and is a good phone.
"If anything, the Duo’s high cost and limited availability only reinforce that Apple’s foldable isn’t for everyone," CNET's Abrar Al-Heetl wrote. "But if you’re looking for something compact that unfurls into a tablet-like experience – and you want to stick with iOS – the iPhone Duo could be the right fit."
For people who aren't early adopters or need to be more mindful of their budget , that high price can be an impediment, and it's unlikely to get cheaper any time soon thanks to the ongoing AI-fueled memory shortage.
Missing camera
Outside of price, the lack of a telephoto lens was remarked on by nearly every review. The cameras are a downgrade compared to the iPhone 18 Pro models.
PetaPixel has more of a camera focus in general, and truly breaks down the cameras in their review, but it can be summarized in one line: "This camera is the epitome of 'fine,' Jaron Schneider said.
He also noted that shooting with the Duo is awkward, lacking a firm grip when closed and feeling like a grandmother with an iPad when unfolded.
Notably, the iPhone Duo's Smart Take feature was praised since it waited for people to enter and pose in frame before taking photos and hopefully that's a feature that comes to other iPhones.
A dim display
For foldable phones, one of the concerns is the crease that becomes more prominent over time as the display is opened and closed hundreds, nay, thousands, of times.
Apple's attempt to obscure the crease mostly works thanks to the nanotexture layer on the display that hides it a bit. This is both a boon, with many describing it as reducing glare and feeling nice to the touch.
Though, as Wired's Julian Chokkattu noted, videos aren't as crisp compared to the iPhone 18 Pro, even if people are watching more content on the larger 7.6-inch inner display. "You don’t get the crisp video quality, deep blacks, and sharp contrast of the iPhone 18 Pro when watching movies and shows on apps like Netflix on the nanotexture panel."
Apple already features the nanotexture display on as an option on the MacBook Pro and Studio Display XDR but If you don't like it there, you likely won't enjoy it on the Duo.
Missing Face ID
We called the lack of Face ID in favor of Touch ID a downgrade in our review. This was a quite common complaint regarding the Duo, with most reviewers finding it quite annoying.
"Touch ID introduces lag versus Face ID when unlocking your phone. Not a lot, just enough to be annoying," Tom's Guide editor-in-chief Mark Spoonauer said. "If you own an Apple Watch, you can unlock your iPhone Duo just by swiping up, but even that’s slower than Face ID."
Heat and weight
I've combined these two because it relates to how it feels to use the iPhone Duo.
"The Duo feels significant and solid," Marques Brownlee said in his review, but compared it to the Z Fold 8, which is 20% lighter. "Making everything metal, glass and heavy doesn't necessarily make it better to use. It's the permanent Apple-design default."
The iPhone Duo weighs 8.96 oz (254 grams) compared to the Z Fold 8's 7.09 oz (201 g). It's not the end of the world, but over time that weight is noticeable, especially if you pick up another company's phone.
As for heat, we noted that the iPhone Duo was a few degrees hotter than the Z Fold 8 in our testing, though it appeared that Apple's phone spread the heat out more.
Joanna Stern found that the back of the phone kept getting "really warm."
"I've consistently noticed the back of the Duo getting surprisingly warm when taking photos, FaceTiming, and using certain apps," she said. In one clip, as she FaceTimed with Casey Nystat, she ended a call because the phone felt too hot.
Software Optimization
The iPhone Duo utilizes a customized version of iOS 27, but it has some flaws, like the fact that lefties are out of luck thanks to the locked dock on the right side of the display.
When it comes to Apple's own apps, the iPhone Duo and iOS 27 are great, with the apps designed to fill the inner display. However, third-party apps aren't yet optimized for the Duo, including apps like Telegram and Disney Plus.
It can make non-optimized apps look terrible, from huge black sidebars to as simple as a sense that the app is a bit askew.
"The difference between optimized and unoptimized apps is the biggest growing pain you'll face on Apple's first foldable," Engadget's Sam Rutherford wrote.
Fortunately, unlike any hardware complaints, this one is more easily rectified since developers can update their apps for the Duo. Or in the case of things like the docked controls, Apple has already promised an update in the coming months.
Anything I missed that you think is a concern? Let me know in the comments below.