The Sony Xperia Z2 has quad-band 2G and penta-band 3G connectivity across all regional models, and support for more LTE bands than you can shake a stick at. The LTE is Cat. 4 meaning it can theoretically reach 150Mbps downlink and 50Mpbs uplink. Outside LTE coverage, the Xperia Z2 is rated for mobile data speeds of up to 42 Mbps HSDPA and 5.76 Mbps HSUPA.
Local connectivity is covered by dual-band Wi-Fi a/b/g/n/ac with DLNA and Wi-Fi Direct, so you can easily share content from your phone on a DLNA TV or music player. If a media app supports the Throw function (like the video player), you can use it through the Smart Connect app for DLNA functions (sharing screen, etc.).
There's also Bluetooth 4.0 with A2DP, which can be used for low-power accessories (e.g. sports trackers). There is also support for the ultra-low power ANT+ connectivity protocol, which is usually used for connecting to various sports accessories such as heart rate monitors or bicycle speed & cadence meters.
The Xperia Z2 features NFC too, but there's no app to handle the NFC functions out of the box. Luckily, there are plenty of capable NFC apps in the Play Store.
MicroUSB handles the charging and PC connectivity, and there's also USB On-the-go support, so you can attach external flash drives to the smartphone as well. The port is MHL-enabled and you can use a compatible HDMI adapter for TV output.
Sony's Smart Connect app comes pre-installed - it allows you to set your device to do a variety of things, like launch an app or set an alarm, whenever you connect an accessory, e.g. a headset or a charger, or during a time interval (e.g. mute alarms at night). It doesn't work with NFC tags though, which is very disappointing.
The Sony Xperia Z2 comes with Google Chrome as the default web browser out of box instead of the generic Android browser. While the minimalist interface hasn't changed since Chrome launched on Android, the browser is being constantly refined by Google, and this has resulted in one of the smoothest and most powerful browsing experiences we've encountered on a mobile.
Of course, one of Chrome's strengths is its ability to seamlessly sync with the desktop version, using nothing but your Google account. This allows you to open an article on your PC and finish reading it on your mobile phone. It also syncs your bookmarks and favorite sites.
Opening the tabs area reveals a list of tabs which can be closed, again with a left or right swipe. The animation accompanying this action is neat, too. Incognito tabs, which lets you browse without saving history or cookies, show up right next to regular tabs.
The calendar has three different types of view - daily, weekly and monthly. The lower section of the screen is reserved for a list of upcoming events. Adding a new event is quick and easy, and you can also set an alarm to act as a reminder.
Sony Xperia Z2 also features the Office Suite 7, which supports creating, viewing and editing office files (docs, xls, ppt), and it can also read PDFs.
Calculator, Clock app (with stopwatch, world clock and timer), Sketch and File Manager apps are available by default.
The Socialife app comes pre-installed too. It is a service similar to Samsung's My Magazine and HTC One's Blinkfeed. The interface is clean and simple yet beautiful, and there are lots of preloaded feeds. You can add your own RSS links too.
There is the Sony PlayStation app too, which allows you to browse your PlayStation profile, avatar and achievements. It's far from Microsoft default Xbox app on Windows Phone, but it's something. It can also connect to your PS4 and extract various content from there.
Sony Select does the same as the Sony's What's New app, but comes with much less functions and old UI. We feel Sony should retire it.
The Power Saver - now part of the settings menu - helps you extend your battery life by toggling things like Wi-Fi, GPS, Bluetooth screen brightness, auto sync and background data on and off automatically when the battery charge falls below a certain user-defined threshold. You can also turn off the Wi-Fi if there is no saved Wi-Fi network in range or turn off mobile data when the screen is off, and more.
Sony also provides a Backup & restore app, which can use the internal storage, a microSD card or even an attached USB mass storage device. You can backup the system and downloaded apps and their data along with any media files.
You bet Google Maps and Navigation are also part of the app package to utilize the built-in A-GPS receiver with GLONASS support. Offline maps are available, again, since the last update, so you can save some data traffic too.
Whatever you may be missing, there is the always-growing Google Play Store for you.