As expected, reviewers mostly judge the iPhone XS and XS Max to be just incrementally better than the iPhone X.
It's worth keeping in mind, however, that most potential iPhone XS buyers won't be iPhone X owners. Rather, they'll be owners of an iPhone 7 or an older Apple (AAPL) smartphone -- products that the XS -- with its edge-to-edge OLED display, faster processor, much-improved cameras and Face ID support -- is significantly better than.
It's also worth keeping in mind that this year's flagship iPhone launch is different from last year's in one rather glaring way that could have a meaningful impact on sales: Apple is rolling out a 6.5-inch model to go with a 5.8-inch one.
Understandably, many reviewers didn't spend much time going over this change. Outside of display size and a few software tweaks, the iPhone XS Max's feature set is virtually identical to that of the standard XS. Thus reviewers generally spent much more time going over the ways in which both the XS ($999 starting price) and XS Max ($1,099 starting price) differ relative to the X, such as revamped cameras, improved battery life, better water/dust-resistance and the use of the A12 Bionic system-on-chip (SoC).
However, for would-be buyers, that extra 0.7 inches of screen size could be pretty important. Whereas the iPhone X and XS have displays that are just fractionally larger than the 5.5-inch displays found on "Plus" iPhones, the XS Max's display is a full inch larger. That's bound to matter to many power users who own one of the Plus devices.
Moreover, since the XS Max has (like the X and XS) no home button and an edge-to-edge display, its dimensions (6.2 inches by 3.05 inches by 0.3 inches) are nearly identical to those of the 5.5-inch iPhones that launched from 2014 through 2017.
Outside of the release of a 6.5-inch model, camera improvements might be the biggest change introduced with this year's flagship iPhones that could have some impact on iPhone upgrade activity. For the most part, reviewers had good things to say about the camera changes, with much attention given to the XS's larger rear image sensor, Smart HDR function and depth-control option for portrait shots.
The larger sensor helps deliver improved focus speeds and better low-light shots. Smart HDR, which represents an overhaul of Apple's efforts to take multiple shots in succession at different exposures and merge them into a single shot, was found by reviewers to improve image quality and detail in challenging environments.
The depth-control feature lets users change a portrait photo's depth of field, and thus the amount of blur that exists for out-of-focus objects, after a shot has been taken. While some Android phones offer a similar feature, Apple's implementation is more advanced and (judging by sample photos) delivers better shots, though some reviewers did note that the feature can be hit-and-miss at times.
Power users might also consider the iPhone XS and XS Max's battery life improvements to be a selling point -- relative to the iPhone X, Apple claims the XS will deliver an extra 30 minutes of battery life under normal use, and the XS Max an extra 90 minutes.
Some might also care about the A12 Bionic's performance gains relative to the A11 Bionic. While only a 15% performance gain is promised for the chip's two high-performance CPU cores, its GPU is said to be up to 50% faster and its AI co-processor (the Neural Engine) is declared to be capable of handling more than 8 times as many operations per second.
Between such enhancements, the XS Max's 6.5-inch display and all the way in which the iPhone X had already improved upon older iPhones, Apple's latest flagship iPhones have enough selling points to drive decent upgrade activity among owners of iPhones launched in 2016 and before. Just as long as their prices don't cause sticker shock.