Samsung describes its new Galaxy S 4 Android smartphone as a “life companion” – a machine of loving grace that uses its array of sensors and accompanying software to discern your interests and tastes and look out for them. It’s only slightly less dramatic to call this the most self-aware phone yet.

If the Galaxy S 4 — available or coming soon on AT&T;, Sprint, T-Mobile and Verizon Wireless, with hardware and two years of service adding up to a low of $2,069.75 at Sprint and a potential high of $2,599.99 at Verizon Wireless – packed in any more sensors, it might need a NASA logo on its side. But a week’s testing of an S 4 loaned by Samsung PR showed that they don’t all work as intended, or as you might want.

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The camera that focuses on you: Where Samsung’s year-old Galaxy S III could use its front camera to see that you were looking at its screen and therefore keep that illuminated, the S 4 can also scroll up or down based on your eye movements.

Right after I activated this option, it felt like I was using the Force to control the phone, but then the camera started mis-reading a flick of my eyes as a signal to scroll up or down, which I then found myself correcting with a tap of a finger. The touchscreen (which can be used while wearing some gloves) doesn’t look obsolete yet.

The touchscreen you don’t have to touch: Or maybe it is! Another S 4 feature, “Air view,” detects when your finger is just above its 5-inch screen to provide previews of content. This looks like serious magic, except that it only works in compatible apps — such as the proprietary calendar app Samsung shipped to replace the simpler program that comes with Android.

The time-and-space-warping camera: The picture-taking tricks in the S 4′s camera let you pull off stunts like embedding a real-time self-portrait in a photo and generating a time-lapse photo of a moving person. But it’s surprisingly hard to keep your face properly framed and exposed in the front camera while also getting a decent photo of the primary subject with the back camera. And that second, “drama” mode exhibits too much drama of its own — it kept complaining that the subject was too far away, too close, or not active enough.

The sensors that remain unused: The S 4 also includes sensors to gauge the temperature, humidity, and barometric pressure-, and none of them appear to be used by any built-in apps. Did adding esoteric capabilities like those get in the way of optimizing battery life? (Despite having a much higher-capacity battery than the S III, it showed less of a charge after 24 hours left idle, 78 percent, than its predecessor did in the same test.)

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I also wonder what Samsung had in mind when it elected to rewrite vast chunks of Android’s interface. The S 4 ships with the most recent version of Android, 4.2, when many phones still await upgrades to last summer’s 4.1 release, but you might not guess that from all of Samsung’s alterations.

Everything from the basic system buttons (the back button’s on the wrong side) to the sort order of installed apps (those you download appear after those bundled with the phone) to the keyboard (it doesn’t correct typos automatically unless you use its Swype gesture-typing option) to its screenshot shortcut (sweep a palm across the screen) differs from what Google ships on phones like my own Nexus 4. What could Samsung do with its engineering and design talents if it weren’t so dead set on revisiting or reversing Google’s work? We’ll never know.

Credit: Rob Pegoraro/Discovery