So far we've been dealing with two phones that do things in sufficiently different ways to make an unequivocal judgement hard to come by, but with the Samsung Galaxy S6 edging it.
Not so with the battery life. The Samsung Galaxy Note 4 storms this category.
It's not that the Samsung Galaxy S6's battery life is bad, as such. It's just not particularly great.
The issue largely revolves around Samsung's decision to pack its fastest and most cutting edge phone yet with a relatively meagre 2,550mAh battery. That represents a drop from the Galaxy S5 (2,800mAh), and it doesn't even get close to the 3,220mAh Galaxy Note 4 in sheer capacity terms.
It doesn't get too close in real world usage either. The Galaxy Note 4 will last deep into a second day with light to moderate usage, while I found that the Galaxy S6 would consistently be left with 20% or so after a similarly undemanding day. Admittedly this varied, but such inconsistency is a worry in itself.
Use both phones heavily, with some gaming and extended music listening thrown in, and while the Galaxy Note 4 will last through until bedtime, the Galaxy S6 will need topping up well before then.
It's a shame, because Samsung has done some good work optimising its newest phone. For example, our regular video test rendered very similar results on the two phones. The test involves playing a 90-minute 720p video with the screen brightness turned right up. The Galaxy Note 4 dropped 11% on average, while the Galaxy S6 dropped 13% – hardly any difference at all.
Aside from battery life, there's also the small matter of being able to removed the battery in the Galaxy Note 4 versus having it fixed in the Galaxy S6. To me this really is a small matter, but some Samsung fans and power users will be put out that they can't carry a spare power unit around with them for the new phone.
While we're talking about nice features that most people don't use, the Galaxy S6 has in-built wireless charging support for the top two standards in the field. Great, if you have a wireless charging dock, but we suspect that this won't fully take off in phones until they start getting bundled in with them, and when they work their way into more public spaces.
Overall, battery life is one area that sees a resounding victory for the Galaxy Note 4.
When it comes to viewing and experiencing media, you can't ask for two better smartphones than the Galaxy S6 and Galaxy Note 4.
You can put that down to those peerless QHD Super AMOLED displays, as well as the snappy processors that run whatever you throw at them without breaking a sweat.
As mentioned when discussing the displays above, while the Galaxy S6 holds the advantage in terms of vibrancy and colour accuracy, the larger canvas provided by the Note 4 arguably makes it better suited to playing video content – particularly of the 2K or 4K variety.
It simply affords those extra pixels more room to breath. Watching a video on any mobile phone is something of a compromise regardless of size, but the Galaxy Note 4 feels the least like one out of all the smartphones I've ever used.
Provided you plug in a set of headphones of course. Neither phone's piddly speaker compares particularly well with the high-end hardware found elsewhere.
Aside from their singular nature, both disappoint in different ways. The Galaxy Note 4's is mounted on the back, so lacks clarity unless you crank the volume right up.
Meanwhile the Galaxy S6's is mounted on the bottom edge of the phone, which is better for low volume clarity, but prone to being covered when held in landscape view.
Samsung's media standard support is typically excellent with both phones. You even get high-res audio support, so you can play those 24-bit/192-kHz music tracks in full ear-bathing glory. Just be sure to do them justice with non-standard headphones, OK?
Add in the fact that the Galaxy Note 4 supports microSD memory expansion while the the Galaxy S6 does not, as well as its superior battery life, and I'd give the media playing nod to the older, bigger phone here.