While the iPhone 5 brought with it an improvement in battery life for the iPhone range, there was still room for more, and to an extent the iPhone 5S delivered.
When we first reviewed the phone the main improvement was the fact that leaving the iPhone 5S on standby, perhaps overnight, sees very little drain on the battery. One night I noticed around 15% drop, but after that it was merely 4-5% on average which I can put down to iOS 7 keeping its apps in order a little better. On iOS 8.1 the battery dropped around 7% overnight, and iOS 9 scores about the same based on the most recent tests run on the handset.
So that's a big problem of the iPhone battery sort of solved: if it's in your pocket, it won't inexplicably run out of juice.
However, there's still a rather large issue I need to address with the battery, and that's the problem of actually using the phone. I test a large number of devices here at techradar, and in the more intensive tests it's always interesting to see which phone fares better.
A little photography, web browsing, video watching and flicking through apps not only warmed up the 5S quite considerably but also saw a rather rapid drain in the battery. For instance: streaming BBC iPlayer on the train home for half an hour saw a 20% drop in the battery life.
I can't see how the claims of eight hours' browsing on 3G holds any water, as that was one area that really hurt the battery and caused the phone to heat up. Talking also drained the power pack, and Apple originally quoted up to 10 hours on 3G back in 2013. Again, I can't see it.
It's not horrendous, and if you're an iPhone user you'll be used to a faster battery drain, but there's definitely a wistful air that hangs over me every time I check out the battery percentage in the top-right corner.
With iOS 7.1 we saw a 17% power drop in our techradar video loop test, which is decent enough, but with iOS 8.1 that became an even larger 25% drop. By the time we ran the test with iOS 9.2.1 that was up to 33%.
With the latest iOS 9.2.1 installed, we were seeing drops of around 15% every half hour when gaming, and a whopping 15% every 10 minutes when using the sat nav in Apple Maps.
There is a caveat here: if you buy a new iPhone 5S from Apple you'll get a brand new battery, not one that's been charging and draining for the past two-and-a-half years like the one in the techtadar test unit – it's pretty much on its last legs.
Those are still disappointing battery scores, though. With a new battery and iOS 9.2.1 (Low Power Mode and all) you might see a significant improvement, but this is a phone that's going to struggle to get to the end of the day if you use it in any serious capacity.
However, here's a great little update that will cheer you up: the iPhone 5S charges phenomenally quickly. REALLY quickly. I timed a charge at just a little over two hours from nearly dead – that's great if you just need a slug of juice on the run.
Unsurprisingly the iPhone 5S comes will all manner of connectivity options, but NFC is still the high-profile absentee at the Apple party. Not even the plastic clad iPhone 5C could tempt the firm to give us a bit of contactless tech, and it clearly paints a picture of where the brand stands in this area.
The latest iPhones and iPads have put Apple's NFC connectivity game on the map, but it's sadly lacking on the iPhone 5S. It's annoying because it means Apple Pay won't work with the iPhone 5S, even though it has the Touch ID component.
It's worth mentioning again that the iPhone 5S sports Wi-Fi a/b/g/n, 3G and 4G connectivity, with special mention of the latter as this phone supports the most LTE bands than any other smartphone of its vintage, allowing even more people to take advantage of the super-fast network.
As is now standard on iOS, the Control Center gives you a quick way to control Wi-Fi and Bluetooth 4.0, which are accessed with a swipe up from the bottom of the screen as mentioned before.
This brings up some shortcut settings, including toggles for both connections, plus you can also enable airplane mode here if you want to go off the grid – or, you know, if you get on a plane.
GPS and GLONASS also make an appearance to help you locate yourself in Maps with earth shattering accuracy (and very quickly, too) and navigate you round the world with the free turn-by-turn satellite navigation system.
The iPhone 5S sports Apple's latest Lightning connection port, so you shouldn't have any problem picking up peripherals or docks for the phone. The same standard is used on Apple's latest phones.
It provides a faster connection than the 30-pin port it replaced, enabling faster data transfer, so you won't be waiting around quite so long. Plus you can plug it in either way round, which saves scrabbling at night.
Apple's own cloud storage solution, cunningly named iCloud, is gradually getting more polished. It enables you to store all your vital information in its secure servers should the worst happen to your iPhone 5S.
You can back up everything from contacts, mail and calendars to photos, documents and notes to iCloud, and if you've owned an iDevice in the past you can download your settings from that onto your iPhone 5S, saving you from having to re-enter various bits of information.
iCloud also enables the 'Find my iPhone' feature, so if you were to misplace your new iPhone you can log onto the iCloud website and see where your phone is on a map.
Once located you have the choice of making play a sound so you can dig it out from behind the sofa, report it as lost or erase the contents of the phone – it's all very clear stuff.
No longer is there a reliance in Apple's desktop iTunes software when you come to starting up your iPhone for the first time – no physical connection ever needs to made to a computer during the lifetime of the 5S if you don't fancy digging out your Lightning cable (although you'll probably need it to charge the handset).
If you do decide it's time for things to get physical between your computer and iPhone then you'll need to make sure you've got the 11.1 and up version of iTunes installed, otherwise it will refuse to play with your new phone.
Why would you want/need to connect your iPhone 5S to your computer? Well perhaps you've got lots of music, movies and photos you want to transfer from your machine to your new phone - iTunes will pull it all in, churn it up and spit it out to your new iPhone in a useable format.
Using iTunes is a rather hit and miss experience, with the software performing far better on a Mac than a Windows PC, but either way it's usually a long, drawn out process which involves lots of syncing - so avoid it if you can, unless you're tremendously regimented in your music organisation.
It's another bit of software that Apple appears to have neglected while it focuses on churning out the world's best smartphones.