It's not often that we're encouraged to break a cell phone that we're reviewing. Most of the time, actually, we're expected to return a handset completely unharmed. Yet, Sonim takes a different, and welcome, approach. Not only does the company challenge us to break its phones, but it helps us try and do so.
That's just what happened with Sonim's latest model, the XP1300 Core. When company reps dropped off the phone at CNET's offices, they were good enough to bring concrete, dry ice, and a bucket of antifreeze. We'll get to specifics of our torture tests in the Design section, but you can be sure that the XP1300 Core, like the earlier Sonim XP3, is built to last. Less impressive was the feature set. Though the XP1300 Core delivers the essentials, there's no camera and there aren't high-end productivity apps. Worse, call quality wasn't quite up to par. The audio clarity was satisfying, but the call volume wasn't sufficient. The GSM XP1300 is sold unlocked for $399.
All that durability comes at a price, of course: the large, bulky XP1300 handset may defy most definitions of portability. At 4.96 inches long by 2.36 inches wide by 0.98 inch deep and 6.52 ounces, it will fit in only the biggest pockets. Honestly, a belt clip is probably the best way to carry a phone like the XP1300 Core. And if that isn't conspicuous enough, you can get it in a striking yellow-and-black color scheme.
The handset's candy-bar shape mimics that of previous Sonim models. The entire handset is wrapped in a tough rubber and fiberglass casing and the battery cover is secured by screws. Protective flaps keep moisture out of the twin 3.5mm ports on the left side. Though the top jack accommodates a standard wired headset, the bottom jack forces you to use Sonim's proprietary connection for charging the phone and syncing it with a PC. Sonim includes the necessary cables in the box, but that's still inconvenient.
The display measures 2 inches and is covered by Gorilla Glass. That makes it resistant to scratches, even if you try to drive a nail into the screen (as we did). The 320x240-pixel resolution isn't eye-popping, but it's more than suitable for this phone. Colors are bright, graphics are relatively sharp, and the revamped menu interface is easy to use. You can change the display's screensaver and wallpaper.
The navigation controls are about the same as on the XP3, though Sonim threw in dedicated Back and Clear controls. The four-way toggle has directional buttons, and we like that the OK control is covered in a rough-textured material. You'll also find two soft keys and the Talk and End/Power keys. They're a tad slick, but it's not a big deal. The redesigned dial-pad keys give you enough space for a comfortable texting experience. The backlighting is bright, as well, though the text on the keys is rather small. Users with visual impairments might want to check it out in person before buying.
The beefy volume rocker sits on the phone's right spine above a control that activates the bright flashlight on the rear side. A programmable shortcut key is on the left side below the aforementioned 3.5mm ports. You can also program the toggle for one-touch access to your favorite features. You'll have to remove the battery cover to access the microSD card slot, but that's understandable in a water-resistant phone.
Sonim makes lots of promises about the XP1300's durability. It's certified to military specifications for salt, fog, humidity, transport shock, and thermal shock; you can drop it on a concrete floor from 6.56 feet (2 meters); it can tolerate temperatures between minus 4 degrees and 131 degrees Fahrenheit (minus 20 degrees and 55 degrees Celsius); you can submerge it in 6.56 feet of water for half an hour; you can cover it in oil; and it can endure pressure of 1,000 pounds per square inch. We subjected it to every test we performed on the XP3, including dropping it on a hard surface, throwing it down the stairs, putting it in a freezer, and stomping the heck out of it with a boot.