Apple's larger of its two 2015 iPhones is 6 percent taller and 5 percent wider than the LG G5. The iPhone, though, measures 5 percent thinner.
LG wins out in the battle of the scales, weighing 17 percent lighter than the iPhone 6s Plus.
Apple's iPhone line has helped define the all-metal unibody design we see so often these days, and other manufacturers (now including LG) are following it.
The LG G5's modular design is its headline feature. You can slide out the base and battery to replace it with different modules, like a spare battery, Hi-Fi music player or camera grip controls.
At this stage we don't know how much these extra components will cost, or how well they're going to work, but it does look like one of the boldest smartphone innovations in years.
We're looking at four color options for each handset.
The iPhone 6s Plus has an 8 percent bigger screen. In an unusual move, LG's 2016 flagship has a smaller screen than its 2015 flagship, which had the same 5.5 inches as the iPhone.
The LG G5 is 38 percent sharper in terms of pixel density. Don't think the iPhone 6s Plus has a bad display though, even if the pixel count is lower. In our experience, its brightness, white balance and color accuracy are all superb.
It's IPS displays all the way, with no love here for the AMOLED displays preferred by Samsung and others.
The 2016 flagship from LG (like Samsung's new phones) has an always-on display, enabling you to check the date and time and see key notifications at a glance without unlocking the phone.
The iPhone 6s Plus doesn't have an always-on display, but it does have its own party trick, in 3D Touch. With a harder press you can access other menus and options within iOS and supported apps.
There's no available Android equivalent to 3D Touch yet, but we haven't found ourselves missing the feature on non-iPhone devices. Handy to have? Yes. Must-have? Nah.
The LG G5 fingerprint sensor is located around the back of the handset underneath the camera. In the case of the iPhone 6s Plus, it's embedded in the Home button on the front.
The LG G5 packs the latest and greatest Qualcomm chip so blazing fast performance should be guaranteed. Apple designs its own processors, so direct comparisons are difficult, but the real-world performance of the iPhone 6s Plus is extremely fast and up there with the very best smartphones of today.
The LG G5 has double the RAM of the iPhone 6s Plus, but don't underestimate iOS' terrific RAM management, which sucks more out of that 2 GB than you'd expect.
There's only 32 GB of storage available with the G5, though the next category helps out some in that department. You also have the option of getting LG's 360 CAM add-on module (that's the camera grip one) which comes with an additional 4 GB.
The G5 supports microSD cards, up to 2 TB in size. Android's Adoptable Storage, where external storage can be treated as internal storage, isn't supported, but you can still make lots of use out of that space (especially handy for photos, videos and music files).
The LG G5 embraces the newer, faster USB Type-C standard rather than microUSB. The iPhone 6s Plus uses Apple's proprietary Lightning connector port.
There's more to battery life than the size of the battery: display demands, software efficiency, power-saving features and so on can all contribute. We'll need to test the G5's juice before jumping to any conclusions here.
Thanks to its Snapdragon 820 processor, the LG G5 supports Qualcomm's Quick Charge 3.0 standard, which improves on the the speed of the (already fast) Quick Charge 2.0 – by 27 percent. As of yet Apple hasn't introduced any comparable fast charging technology for iPhones.
Sorry, wireless charging fans, but neither the LG G5 or the iPhone 6s Plus are going to give you what you want (at least not without an additional accessory or wireless charging case).
As we mentioned, the modular design of the LG G5 means you can remove and replace the battery. In addition to the regular battery replacement module, the LG 360 CAM plug-in module offers an extra 1,200 mAh of juice over the standard battery.
LG has joined the virtual reality revolution with its positively meh (at least based on our demo) LG 360 VR accessory for the LG G5. It's a lightweight VR headset that plugs into the phone (unconventionally) via a standard USB Type-C cable.
For the time being Apple is staying out of the VR market, but there are almost certainly plans being made behind closed doors. In the meantime, the Samsung Gear VR delivers the best mobile VR and the HTC Vive and Oculus Rift the best VR, period.
LG wins in terms of pure megapixels but we'll have to wait for a review unit before we know whether it can compete with the excellent camera Apple has put inside the iPhone 6s Plus.
Notably, the LG G5 has a dual-lens camera around the back, with the smaller 8 MP lens coming with a 135 mm wide-angle lens that lets you get a wider shot if and when necessary.
Camera aperture (rear)
The LG phone camera has a wider aperture, which should in theory translate into better low light performance – though again we'll have to put the LG G5 through its paces properly before giving a final judgement.
Optical Image Stabilization is present on both handsets, cutting out blur and camera shake when your hands aren't perfectly steady.
It's Android 6.0 Marshmallow vs. iOS 9, which is likely to be one of the bigger decisions you need to make if you're choosing between these two phones. LG does have its own custom UI sitting on top of the core software, though, so it isn't quite Google' purest vision of its newest OS update.
LG's new handset goes on sale in April together with its LG Friends accessories. Apple's iPhone 6s Plus launched last September.
Starting price (full retail)
At the time of writing we don't know the price point of the LG G5. The cheapest iPhone 6s Plus, the 16 GB edition, can be picked up for $749 full retail without a contract.