iPhone 6S Review Roundup
Beyond the shiny new upgrades, the iPhone 6S still retains some of the flaws of its predecessor. Reuters/Beck Diefenbach

Reviews poured in Wednesday for Apple’s latest smartphones --the iPhone 6S and the 6S Plus. The consensus? This is the best smartphone on the planet. But that title still comes with caveats. Five of them, actually.

Reviewers generally praised the iPhone 6S and the 6S Plus for features like their pressure-sensitive 3D Touch displays and upgraded cameras. One test put the phone's A9 chip as faster than a late-model MacBook. But reviewers hated some things, meaning Apple has its work cut out for the iPhone 7.

Better Battery Life Is A No-Show

The iPhone 6S may have received an upgrade across the board internally. But that somehow didn’t make it into battery, as the Wall Street Journal’s Joanna Stern discovered:

“The No. 1 thing people want in a smartphone is better battery life. And the iPhone 6s doesn’t deliver that. The 4.7-inch 6S will get you through the day, but you’ll struggle to make it til bedtime with moderate to heavy use. And it seemed to drain even faster than my 6 when I used the new processor-intensive camera features like Live Photos.”

Camera Upgrade Not Readily Noticeable

After years of sticking with an 8-megapixels sensor on various iPhone cameras, Apple upped the count to 12-megapixels with the iPhone 6S. But as Yahoo Tech’s David Pogue pointed out, the difference between the two cameras aren’t easily discernable.

“Now, it’s not a slam to say that photos taken with the 6S don’t look any better than those captured on an iPhone 6; the iPhone 6 camera was already among the best ever put into a phone. But you shouldn’t expect a leap forward in most of your shots.”

Slippery Back

Re/Code’s Walt Mossberg praised the iPhone 6S for a lot of its internal improvements. But he notes that the iPhone 6S still carries some of the problems of its predecessor, especially its rear case that can be difficult to keep a grip on.

“The back of the phone can be a bit slippery, especially because it has rounded edges. That made the iPhone 6 the first model I have ever felt the need to use with a case, and the same applies to the 6S.”

Live Photos Take Up A Ton Of Space

With the iPhone 6S, Apple introduced a new feature called Live Photos, which captures a second or two before a picture is taken and a second after to create a short video clip. But all that extra information takes up even more space, as The Verge’s Nilay Patel noted.

“Live Photos take up double the space of regular photos, so having every single photo you take include a short video seems like major overkill. I would play with it for a while then flip it off and turn it on when you need it.”

Base Model Is Still 16GB

Apple introduced a number of new features that take up more space on the iPhone 6S, such as Live Photos and 4K video recording. But one area it hasn’t addressed is its base model, which still sits at 16GB, Mashable’s Christina Warren pointed out in disappointment.

“That extra size [for Live Photos] makes me even more disappointed that Apple decided to keep the 16GB option available for the iPhone 6S. It just seems silly.”

The iPhone 6S and 6S Plus officially goes on sale Friday in Australia, Canada, China, France, Germany, Hong Kong, Japan, New Zealand, Puerto Rico, Singapore, the U.K. and the U.S. The iPhone 6S starts at $649 and the 6S Plus starts at $749 for the 16GB model. But prices may vary in each market.