For calling, the iPhone 5S doesn't bring much that's new to the table other than a few more LTE bands. It can function on pretty much any next-gen network around the world.
If you're in the UK, this means that you'll be able to connect to 4G on the likes of Vodafone, O2, EE and Three without a worry – something that will have been a hindrance to those wanting to connect to the super speeds with an iPhone 5.
I tested the iPhone 5S on EE's network in the UK, and was mightily impressed with the results - which makes sense, given 4G is all fast and that.
When there's a full signal, the phone is blisteringly quick over 4G, although when a couple of bars (or spots as they are now) drop off, the speeds can slacken quite measurably too.
However, unlike its predecessor, there's a real feel that the iPhone 5S is a handset designed for 4G – although running at the faster connection does seem to cook the battery somewhat.
The call quality on the iPhone is nothing to shout about, with the slightly sharper edges of the phone making it even harder to hear people due to reticence to push it closer to your ear hole.
The sound quality emanating from the earpiece is decent without being stonkingly clear and there's not much in the way of audio enhancement to play with. It's worth noting that on rival handsets there's always a lot more that you can do to improve things in this respect.
In terms of the other person being able to hear you, things are more impressive, thanks to three microphones that enable excellent noise cancellation and can pick up a wide level of what you're trying to say.
But therein lies the rub - is that too simplistic? To one person, being able to calibrate the sound levels of the Samsung Galaxy S5 is a great thing to be able to do, and they'll do so willingly. With the iPhone, many prefer simplicity, so the ability to be able to just press a button, make a call with a nice interface and move on will impress many.
There's no smart dialling here though - that really irks as it's an excellent method of getting to your contacts through the dial pad. Android 4.3 and up has it baked into the OS, and it feels high time Apple did the same thing.
iOS 7.1 brought a slight upgrade to the Phone app, with the buttons turned from large coloured rectangles to circular buttons to match the dialling pad - it's a subtle change that I didn't really care about when first hearing of it, but does look more aesthetically pleasing.
Maybe Sir Ive was bored in a meeting and re-tooled them.
Facetime has been given a cheeky boost too thanks to the improved front camera, which displays really fast and clear images provided you've got a strong enough connection.
Is it ever going to take over the world in the way voice calling did? Nope, not even with an HD front facing camera. It's better though, and really helps with those lonely hotel trips.
The contacts on the iPhone are still rather dismal, and still something that Apple needs to address. I want far more than the list of contacts on offer, despite the list of letters at the side of your address book being very easy to slide down.
It's a lot better than it was, allowing you to enable Facebook and Twitter to update your contacts book with pictures of friends when all the data matches.
But compare that to pretty much any Android phone now and you'll see the disparity: here you have to hope that things match in terms of email or other information and the iPhone will deign to connect them together.
If this fails, it's far from simple to have everyone matched up, so no high-resolution profile pics, no updates on what your friends are doing from within the app, and generally not a lot going on at all.
Apple could do so much more with the matching here, but it's a sticky mess if you want to link anyone together.
It's not a bad contacts system, it just could (and probably will) be so much better in the future.