THIS phone is going to be big. Not just because of its five-inch display.
This is Samsung's flagship phone and the marketing budget means that if you haven't heard of it already, you will.
But it's also a highly capable phone that's jammed with so many features and innovations it'll take time to get acquainted with them all.
The Samsung Galaxy S4 is the sequel to, that's right, the Galaxy S3, the smartphone which was so successful that for several months last year, it outsold the iPhone.
Samsung is hoping this phone will perform the same trick.
Take a quick glance and you might think you're looking at the S3.
Comfortingly familiar, then, if you liked last year's model. But look again and you'll see that though the frame looks superficially similar, it has a sleeker, slicker look with fewer curves.
It's altogether a classier-looking phone. And though it's not bigger in any direction, and thinner from front to back, this phone has a bigger screen and much more tech inside. How did they fit it all in?
In the hand, the ultra-smooth, glossy plastic feels good, and though it's big, it doesn't feel oversized when held to the ear.
Call quality - you know, that thing we all need and we reviewers sometimes pass over - is strong, with good signal strength.
This is a phone smooth enough to roll in your hands like a worry stone, even if it doesn't match the high-end glamour of its stunningly beautiful, metal-clad rival, the HTC One.
But this is a slim, tactile machine that doesn't feel anywhere near as big as the screen size suggests.
It's comfier in the hand than that other five-inch-screened phone, the Sony Xperia Z, more substantial than the iPhone 5.
The joins here are so smooth it's a surprise to find that the back is removable - most high-end rivals seal the battery in to maximise space inside and to give a solid feel.
Still, there is barely a hint of creaking even if you flex the phone in your fingers. And the advantage is you can swap the battery out if you're running out of juice.
Turn it on and the fun starts.
The display looks spectacular thanks to its Full HD (1920 x 1080) resolution, the same as on the biggest HD TV.
It's vivid because it's a Super AMOLED display (Advanced Matrix Organic Light Emitting Diode, if you must know) and nobody uses this technology as effectively as Samsung.
Video playback looks pristine, everything looks pin-sharp. The 441 pixel-per-inch count is way higher than the iPhone, and is beaten only by the HTC One. This is a deeply impressive screen - everything is crystal-clear.
It's not all about the specs, though Samsung has made sure it has the latest, whizziest components.
There's a fast processor, 4G compatibility, even an infra-red transmitter that turns the phone into a TV remote control.
The camera has a high-resolution sensor - 13 megapixels - and there's a two-megapixel front-facing camera. But it's what the hardware is used for that sets the phone apart.
Samsung uses the front camera for more than video calling: its primary purpose on other smartphones, apparently, though do you make video calls? Ever?
Here, though, the camera watches your eyeballs.
Last year's Galaxy S3 introduced this tech, using it to dim the screen when you weren't looking at it.
Now, there's Smart Pause so when you glance away from the video you're playing back, the screen freezes, resuming when you look back. It doesn't sound much but it's actually fun, and works perfectly.
There's also a feature called Smart Scroll which, once your eyes have been detected, scrolls the content of the web page you're viewing, say, when you reach the bottom. You activate this by tilting the phone, or your head. This is less immediately useful, so you may find you're turning it off.
In fact, given that this is a touchscreen phone, there are plenty of ways to interact with it without touching.
Apart from Smart Pause etc, you can turn the screen's sensitivity up so that it recognizes your fingers are there even when they're not quite touching, for instance when you have gloves on. Many of Nokia's Lumia phones have this feature and it's definitely useful.
Hover your finger over a contact name in the address book and the phone opens a preview window to show more information - this is useful but realistically not much more effective than touching the contact to open it.
On the other hand, using the air gesture to move down a web page without touching is convenient if you're reading a recipe, say, and your hands are covered in cooking oil.
Some of these features feel very much like gimmicks that you'll use a few times and never again, but there are so many of them there are likely to be some you'll find useful.
For instance, Direct Call, which arrived on the Galaxy S3, is enjoyable: when a friend's phone number is onscreen, simply raise the phone to your ear and it'll dial the number automatically.
My favourite is Quick Glance. Wave your hand over the phone when the screen is off and a starry sky gently lights up to show time, date, missed calls and battery level before fading out again. This feels both intimate and slightly eerie.
The many features include some real gems.
Translator allows you to speak into the microphone and the program turns your words into onscreen text, translates it as text and speaks it.
There are plenty of languages to choose from and providing you speak clearly, voice recognition is excellent. I can't speak for the quality of the translation but, hey, that's the point of the app, isn't it?
The only downside is it needs a data connection to work and if you're using it, chances are you're abroad so your roaming costs may be astronomical, or astronômico as they say in Brazilian Portuguese.
Google's Android software is endlessly customisable. Nobody does this better than HTC, with its elegant icons and nifty apps.
Samsung's take isn't as stylish but the apps here have an excellent clarity and simplicity.
And while Samsung's own-brand apps aren't known as class-leading, the phone is set up in a way that's accessible to newcomers, with the weather clock, Google search box, email and camera all readily found on the default home screen.
Many people won't feel the need to change any of these apps or move their locations.
For many, this phone will be just too big. For some it won't be premium-looking enough. And it will be just too gimmicky for those wanting a simple experience.
But there's no doubting this is a highly efficient, capable smartphone with more features than you can easily use.
It's a real powerhouse that is attractive as well as brainy. It has features aplenty and - thanks to that removable battery - staying power that will see you through a full day's usage with ease. It will be a big success. And it deserves to be.