Sony Xperia Z1 vs Samsung Galaxy S4
Interface and Functionality
Both the Xperia Z1 and the Galaxy S4 are currently running Android 4.2.2, and of course, we're treated to custom user experiences on both phones. On the Xperia Z1, we have Sony's custom UI, which covers pretty much all of the core OS applications. The same goes for the Galaxy S4, which features Samsung's TouchWiz Nature UX. As far as polish and uniformity goes, we'd say that Sony has done a better job overall, but in terms of bonus features, Samsung has created one really impressive list of additional goodies, including S Health, Samsung Hub, Samsung Apps, S Beam and so on and so forth.
Processor and Memory
Having the benefit of coming out half a year later than the Samsung Galaxy S4, the Sony Xperia Z1 features the more powerful Snapdragon 800 chipset, which outpaces the Snapdragon 600 found in the GS4. The Z1's Snapdragon 800 SoC features a quad-core Krait 400 CPU clocked at 2.2 GHz, while the quad-core Krait 300 powering the GS4 has a clock rate of 1.9 GHz. Of course, in some regions, the Galaxy S4 also comes with the octa-core Samsung Exynos 5 Octa CPU, which is clocked at 1.6 GHz.
We can't be sure if its only due to the faster processor, or the software on the Z1 is also helping out, but Sony's handset is moving more fluidly compared to the Galaxy S4, which exhibits some lag every now and then. Of course, it isn't anything deal-breaking, but it's just nicer when your phone is completely lag-free, and that's something the Xperia Z1 can offer you.
Furthermore, the Adreno 330 GPU of the Xperia Z1 is also more powerful than the Adreno 320 of the Galaxy S4. You'll still be able to enjoy all the games and applications on both phones, but it's safe to say that the Xperia Z1 will be just a bit more future-proof in that respect. Theoretically, the Adreno 330 should offer a beefy 50% increase in performance over the 320.
Memory-wise, both handsets are quite identical, as both feature 2 GB of RAM, which is plenty of system memory every way you look at it. When it comes to storage, the Galaxy S4 gives you a bit more flexibility, as it comes in 16, 32 and 64 GB variants, along with microSD card support, while the Sony Xperia Z1 is only available with 16 GB of internal storage, though, thankfully, it also features a microSD card slot.
There isn't anything shocking or irregular when it comes to the contacts applications on both phones. Still, we tend to prefer the phonebook of the Xperia Z1, due to its cleaner and more intuitive design. However, what we don't like about this one is how the dialer and call log share the same screen, leaving a limited amount of space for your recent calls — and we know that's the screen which many people use to dial their contacts. This problem isn't present on the Samsung Galaxy S4, where there are separate tabs for the dialer and the call log, however, the GS4 lacks a tab for the contact groups, while such is present on the Z1.
Thankfully, we like how both devices offer us the option to find our contacts using smart dialing, or in other words, by using a T9-style typing in the dialer.
The Xperia Z1 and Galaxy S4 sport all the must-have organizer tools, such as versatile note apps, voice recorders, calendars and so on. There are certain differences between the two, of course. In general, Samsung's offering tends to offer a bit more flexibility and options, while Sony's apps have more simplistic and well-designed layouts. If we have to pick one, we'd choose the Sony, due to its less cluttered and efficient approach, but, you know, the Galaxy S4's software isn't bad as well and may appeal to a lot of people.
Those things that we said about the layouts of the apps a bit earlier are fully valid here as well, as we do prefer the clearer interface of Sony's Email app. Sure, you can always grab a third-party one if you don't like what's coming built-in, but if you'd prefer to stick with the stock software, the applications on the Xperia Z1 prove to be slightly more convenient to use, with regards to the user experience.
While the Galaxy S4 comes with two browsers, Chrome and the custom Samsung one, the Xperia Z1 has totally ditched any custom solutions in favor of Google's own browser. Having a second browser doesn't hurt, of course, but we tend to be fans of the more streamlined experiences, which is what the Xperia Z1 will offer you. Samsung's custom browser used to be quite useful when it was significantly faster than Chrome and featured support for Flash Player, but at this point we no longer see that much use in it.
As you can imagine, these two flagship smartphones are choke-full of connectivity features. In terms of data connection, the Xperia Z1 trumps the Galaxy S4 by offering LTE Cat4, which comes with support for downlink speeds of up to 150 Mbit/s, while the GS4's LTE Cat3 can, theoretically, go up to 100 Mbit/s. LTE upload speeds are the same for both handsets and go up to 50 Mbit/s. Of course, you should keep in mind that these are theoretic speeds, and one will rarely have the opportunity to experience them in real world situations. Other than that, there's HSPA+ on both phones enabling download speeds of up to 42.2 Mbit/s and 5.76 Mbit/s upload.
Naturally, you also get all Wi-Fi protocols, Bluetooth 4.0 and a seamlessly-working GPS on both devices, along with DLNA and NFC. The Galaxy S4 also supports MHL and infrared in order to extend its list of connectivity features even further.