Sony hopes to tempt potential phone shoppers with the Xperia Z's unique mix of durability, sexy design, and a powerful camera. Now available for preorder at T-Mobile for $99.99 down (and 24 payments of $20 per month) and hitting stores on July 17, it's billed as the company's top mobile device and has a lot to prove. Sadly, the Xperia Z's pokey imaging system and short battery life can't stand up to the likes of the HTC One and Samsung Galaxy S4, both sold by T-Mobile for the same up-front price. Those competing gadgets add up to better buys, that is unless you absolutely must have a water- and dust-resistant smartphone.

Design

Looking more like a mysterious monolith than your average smartphone, the Sony Xperia Z's almost featureless rectangular shape doesn't give up its secrets easily. Its glossy black, all-glass chassis has a smooth surface that's practically blank and a front face devoid of any physical buttons.

A 3-megapixel front-facing camera, tiny notification light, and earpiece above and a minute speaker below are the only distractions from the Xperia Z's huge 5-inch screen. As a matter of fact, the phone's sole tangible controls sit on the Xperia's right edge -- a large circular power key placed next to a trim volume bar.

That doesn't mean the handset lacks the typical allotment of ports and connections. On the contrary, the Xperia Z hides them under protective flaps to guard against rude intrusion from dirt and liquids. Indeed, Sony claims that the Z meets the IP55 and IP57 international protocols for durability. That means you can immerse the phone in up to 3 feet of water for 30 minutes without any issues. The same goes for exposure to dust and other fine particles, which will have a hard time slipping through the Xperia Z's defenses to its sensitive electronics.

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Located on the left side is a Micro-USB port for charging and for transfering files, and a slot that accepts a microSD card for additional storage memory. Under a flap on the right side is the phone's SIM card slot. Up top you'll find a 3.5mm headphone jack, also tucked away under a protective cover.

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Despite the Xperia Z's enhanced durability, it remains extremely thin, flat and pocket-friendly. Measuring a mere 0.31 inch thick by 5.47 inches tall and 2.79 inches wide, I found it svelte enough to slip into tight jeans pockets and compact enough to lose in messenger bags. That said, the phone's angular edges and flat back make it less comfortable to hold than the HTC One and Samsung Galaxy S4, which have gently curved backs. The Xperia Z's battery is also embedded, so you can't swap it out for a fresh power pack in a pinch.

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Another hit against the Xperia Z's design is its slick, or more accurately, too-glossy surface. Hey, I like to think of myself as a relatively hygienic individual. I take showers daily and frequently wash my hands, a necessity for living in New York City. Unfortunately the Xperia's glass chassis attracted face grease and fingerprints almost instantly when I handled it. I guess Sony figures you can simply run the phone under the faucet to get it squeaky-clean in a flash.

Screen

Sony makes a point of praising the Xperia Z's 5-inch full-HD-resolution display (1,920x1,080 pixels), and with justification. It's big and bright and produces vivid colors for enjoying photos, video, or documents and text. Even so, when I viewed the Xperia's screen side by side with the HTC One (both set to maximum brightness) I found the One's display brighter and more uniformly lit -- even seen off-angle.

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By comparison, the Xperia Z's screen dimmed dramatically when I tilted it either horizontally or vertically. Additionally, while the Samsung Galaxy S4's AMOLED display doesn't get as bright as either the Xperia's or the One's, it trumps both in terms of lusciously dark black levels and richly saturated colors along with extremely wide viewing angles.

Software and features

With its current line of handsets, Sony has finally upped its software game. Just like the less rugged Xperia ZL, the Xperia Z features all the modern capabilities of Android 4.1.2 Jelly Bean. This includes seamless integration with Google's large stable of services such as Gmail, Google Talk, and Google Plus social networking.

It's not the most recent version of Android, version 4.2, but only a handful of phones currently boast this, such as the LG Nexus 4, HTC One Google Play Edition, and Samsung Galaxy S4 (both carrier-branded and Google Play Edition models).

You also get support for the Google Now advanced search and virtual assistant plus a corresponding widget. In addition to letting you use voice commands to set reminders and check your schedule, Google Now provides automatic search results and timely information based on your location.

Best of all, the feature will adapt as you use it more, showing the information it expects you to value most. In my case that happens to be New York Mets scores and stats -- you know they're looking pretty good this year!

T-Mobile managed to slip a few of its own apps onto the Xperia Z as well. There's a My Account application to check up on your billing, data usage, and other phone plan information with. The T-Mobile TV app serves up both canned and live video programming from the likes of Fox, Disney, ESPN, the AP, and Bravo. Keep in mind that to watch anything other than Fox and the AP the service costs an additional $9.99 per month.

Sony's special sauce

The Xperia Z doesn't run vanilla Android. Rather, Sony has grafted its own UI on top of Google's operating system. Thankfully it's a light alteration consisting mainly of a tweaked lock screen and notification shade. For example, the Xperia lets you jump straight to the camera or music player from the lock screen. The phone also offers six home screens instead of plain Android Jelly Bean's five.

Of course this wouldn't be a real Sony smartphone if it didn't hawk content from the company's library of digital entertainment, called the Sony Entertainment Network. A Video Unlimited app serves up movies and TV shows for download, either to rent or purchase. Be warned, though, that once you rent video and begin playing it, you have up 24 hours to enjoy it. After this time period expires, it vanishes in a virtual puff of smoke. Additionally you're locked into viewing video content on the specific phone you downloaded it to.

The Music Unlimited application lets subscribers listen to streamed or cached songs in addition to a range of genre-based music stations, provided you pay a $9.99 monthly fee. The only way to download music to the phone for listening offline, however, is to add tracks to a playlist, then set that playlist for offline access. You also must kick the Music Unlimited app into offline mode. Needless to say I found all the steps required to watch and listen to Sony's digital content on the Xperia Z add up to a confusing and often frustrating procedure.

Performance

The Sony Xperia Z comes equipped with a potent 1.5GHz quad-core Snapdragon S4 Pro processor backed up by 2GB of RAM. That's enough horsepower to drive the phone's Android software at a quick clip; I didn't run into any serious hiccups, whether flipping through home screens or launching apps. Still, the Xperia lacks the pep and verve I've come to expect from competing flagship handsets such as the HTC One and the Samsung Galaxy S4.