With the iPhone 6s, Apple has upped the ante in the perennial showdown between the two leading smartphones.  So, what’s changed?

iOS 9

Just released this week, there is little visually to distinguish iOS 9 from iOS 8 but there are some definite improvements. For example: a smaller footprint (the update requires only 1.3GB, about a third of the 4.58GB space needed for iOS 8), better battery life (up to an additional hour and even more with Low Power Mode), faster performance (e.g., smoother scrolling, animations), and boosted security with the option for 6-digit passcode instead of just 4. And Apple has added 3D Touch, a feature it talked a lot about when announcing the 6s earlier this month: depending on how you press the screen, you can trigger actions like getting a peek at the contents of an email or getting a look at a website before you go there.

Related: Early signs indicate strong demand for Apple's new iPhone 6s and 6s Plus

But Apple is also playing catch-up to Android (which the Galaxy S6 uses, though overlaid with Samsung’s TouchWiz interface).  Siri, for example, now offers suggestions of what app you’ll want to use next, a feature Android has perfected with Google Now (and some would say is still ahead of Apple). iOS 9 also features a “Back to” strip at the top left of the screen – for switching between apps – a capability Android has had for years. 

A9

As Apple typically does with the “s” iPhones, it has bumped up the internals but left the external design alone.  The biggest single internal change is the new A9 processor.  It’s Apple's third generation of 64-bit processors. Not surprisingly, the A9 is faster than the previous-generation A8 (up to 70 to 90 percent faster, depending on what it’s doing).  Faster processors mean snappier apps, better gaming, and higher-resolution video – to mention just a few. 

Related: Apple unveils iPad Pro, new iPhones, revamps Apple TV

All of that applies to Samsung’s newest processor too. The latest 64-bit Exynos processor (designed by Samsung) inside the Galaxy S6, the Galaxy S6 edge, and Galaxy S6 edge+ is also capable and fast. Bottom line: Because it’s such a critical component, both Apple and Samsung have become very adept at making fast, cutting-edge silicon.  iPhone and Galaxy owners aren’t going to notice any glaring differences in most cases. 

Camera

For reviewers, this is often at the top of the list because a smartphone’s camera is the only camera for many consumers now.  Apple didn’t disappoint with the 6s.   It has stepped up to a 12-megapixel camera (after sticking with 8-megapixels for the last several years) and introduced more advanced individual pixel technology too.  

Related: iPhone 6s: The 9 best new features

For Apple, the camera upgrade was absolutely essential because the 16-megapixel camera in the Galaxy S6 is a big improvement over previous Samsung cameras and it has received more than a few glowing reviews.  Has Apple leveled the playing field? We’ll know in the coming weeks. 

External design/display

This is the part that hasn't changed at all on the iPhone 6s. In keeping with past Apple s upgrades, the 6S looks just like the 6 (and the 6s Plus is identical to the 6 Plus). It's worth mentioning because Samsung has been busy making changes to its Galaxy flagship phones.  The Galaxy S6 edge and edge+ have curved displays that wrap around the edges.  While some reviews have questioned the practicality of the edge screen (e.g., “tricky to hold”) it’s nevertheless a big departure from the standard flat screen. Samsung also offers larger displays with better resolution: the S6 has a 5.1-inch display versus the iPhone 6s’ 4.7-incher and Samsung squeezes in the larger display without making the S6 appreciably bigger than the iPhone 6s.

Conclusion

Any lead (real or imagined) that Apple has over Samsung’s S6 with the iPhone 6s won’t last long. But expect a lot more attention focused on the 6s in the coming weeks and months since it’s the new kid on the block.