There are differences in the available apps too. Not as many as their once was, with both OS's offering well over a million apps, but iOS has a slightly better selection of premium ones. On the other hand Android is stillthe more open and customisable OS.
The other difference is as much a screen technology as an OS feature, but with 3D Touch the iPhone 6S can tell the difference between different amounts of pressure when you're tapping and a light press will often result in a different outcome to a hard one, giving you one more way to interact with the device.
One thing which didn't overly impress us about the Samsung Galaxy S6 Edge was its battery life, as its 2,600mAh juice pack struggles to see it through a day if you use the handset as more than just a phone.
While we're not expecting amazing things from the iPhone 6S's battery the suggestions from Apple are that it should have the same longevity as the iPhone 6, which would mean a little more endurance than what we've seen from Samsung's phone, so you'll hopefully at least be able to get to bed time before plugging it in.
Still, the Samsung Galaxy S6 Edge does support fast charging, so if you need to juice it up part way through the day you can do so quite quickly.
Price and availability
The Samsung Galaxy S6 Edge is currently available from around £460 ($600, AU$1000), while the iPhone 6S retails for £539 ($649, AU$1,079), so Apple's phone is a little more expensive in most regions, but then it's also newer, so that's to be expected. Neither phone is cheap though, with both packing flagship prices.
The Samsung Galaxy S6 Edge is widely available though and while the iPhone 6S is sure to be sold just about everywhere it's going to be in high demand, so it may sell out.
With the Galaxy S6 Edge Samsung has finally made a flagship that can compete with the aesthetics of the iPhone as well as the specs.
Both handsets look great, they're both powerful and both have fingerprint scanners. The iPhone 6S is likely to be able to rival the S6 Edge's impressive camera too and it might also achieve better battery life.
It's a little more expensive though and it doesn't have as sharp (or as curvy) a screen. It's too soon to say for sure which phone is best, but they're both clear flagships that do their makers proud.
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James is a freelance phones, tablets and wearables writer and sub-editor at TechRadar. He has a love for everything ‘smart’, from watches to lights, and can often be found arguing with AI assistants or drowning in the latest apps. James also contributes to 3G.co.uk, 4G.co.uk and 5G.co.uk and has written for T3, Digital Camera World, Clarity Media and others, with work on the web, in print and on TV.