In typical Apple fashion, some key specifications are leaving us playing a guessing game. While Samsung was happy to reveal the exact capacity of the Galaxy Note 4's battery: 3220mAh, Apple remains coy about listing the capacity.
So far it has only revealed expected usage times in a variety of scenarios: 80 hours of audio, 14 hours of video, 12 hours of Wi-Fi, LTE or 3G usage and up to 16 days standby.
Samsung on the other hand, has not yet listed detailed battery life expectations. However, with a battery that size it should be as good, if not better, than the iPhone 6 Plus.
Again, it's difficult to provide a direct comparison of performance between these two giant phones, as Apple is holding its cards close to its chest.
All we know so far is that the iPhone 6 Plus packs a dual-core 64-bit A8 processor - an upgrade over the 5S' A7 processor, with Apple claiming that it is 25% faster, with 50% faster graphics.
The specifications of the Samsung Note 4 are a little easier to digest, packing the first Qualcomm Snapdragon 805 processor to feature in a smartphone, clocked at 2.7GHz.
This coupled with an Adreno 420 GPU should be ample power to Android L and all that comes with it. Some markets will see an alternative octo-core processor that packs quad-core 1.3Ghz and quad-core 1.9GHz processors and a Mali-T760 GPU into one system-on-chip.
The biggest disparity between the two is the RAM. The Galaxy Note 4 has a whopping 3GB of RAM, where as the iPhone 6 Plus is reported to feature just 1GB of RAM.
Apple didn't directly qualify this in its keynote, but it's likely to be both correct and equally unsurprising. iOS is rather more resourceful with its memory, despite more limited multi-tasking capabilities than Android. With an efficient processor, less RAM doesn't make any noticeable difference in real world usage.
Apple has finally introduced a 128GB version of the iPhone 6 Plus (and in the process quietly killed off the iPod Classic), alongside 64 and 16GB models. Samsung's Galaxy Note instead offers 32GB or 64GB varieties, but has the added bonus of a micro-SD card slot capable of housing an additional 128GB of storage.
Health & Other Features
Both Apple and Samsung have packed a wealth of features into these latest, and largest of smartphones, with health tracking sensors taking high priority in both devices.
The Apple iPhone 6 Plus packs a barometer, next-gen gyroscope and more. Samsung has included these and gone a step further by including a rear-positioned heart rate sensor and UV meter that combine to produce a wide range of health and fitness feedback.
Apple includes the Touch ID fingerprint scanner on the home button, but Samsung counters this with its own equivalent positioned underneath the screen just above the home button. However, with the launch of the iPhone 6 Plus Apple has shown that a fingerprint scanner affords considerably more possibilities beyond unlocking your smartphone.
Apple has finally managed to coerce the major card providers - Visa, Mastercard and American Express - into introducing a digital payment system called Apple Pay that combines NFC, Touch ID and the card information apparently "securely stored" in the Passbook app.
It's no surprise that to get the most out of either of these new smartphones, both will tell you that complementary smartwatches - the Samsung Gear Live and Apple Watch - are key to ensure you get the most information and best experience.
Samsung hasn't yet officially announced pricing for the Note 4, though you can expect it to be more expensive than the Galaxy S5, which had an RRP of around £550-£600 SIM free in the UK, $650+ in the US, and $900 in Australia.
The iPhone 6 Plus' SIM-free price starts at a sizable $749, £619, AU$999, which means it's probably going to be more expensive than the Note 4.
Unsurprisingly, all the major UK networks have committed to stocking both phones, with EE getting a special mention in Apple's keynote for Wi-Fi calling capabilities.
Pre-orders of the Apple iPhone 6 Plus start on September 12, and it will go on sale in the US, UK and other territories on September 19.
Much like the details of its pricing, the Samsung Galaxy Note 4 launch date is still officially unknown, though it is expected to start appearing on the shelves sometime in October.