The Nvidia Shield Android TV box tries to straddle two galloping horses headed in different directions. It's a difficult and potentially painful balancing act.

One plucky palomino is the world of media streamers, represented by the Chromecast, Amazon Fire TV, Apple TV and Roku. They're all cheap, work great (more or less) and are only growing in popularity and app support.

The other raging stallion is the gaming world, in the form of the Xbox One and PlayStation 4. They're significantly more expensive than the Shield, but they're superior gaming devices. Most serious gamers have one or the other, or an even more expensive gaming PC.

Doing the splits in the middle is the Shield, which starts at $200 or £150. It uses the Android TV streaming media and app platform, which has solid voice search, Google Cast functionality just like a Chromecast, a pushy interface and fewer native apps than competitors.

Android TV has access to a limited library of apps compared with the Google Play Store for phones and tablets, and still lacks Amazon Instant Video, Watch ESPN and Spotify apps among others. Fire TV and Roku have a better selection of native apps, although neither has the Shield's Google Cast capability.

If you have an early 4K TV that lacks built-in 4K streaming apps you might be tempted by the Shield's 4K capability, but the less-expensive Roku 4 is the better choice. The Shield might also appeal to people who have large libraries of Android games they want to play on a TV, or are interested in streaming a selection of older games for $8 per month. If any of those people actually existed.

There is one group of buyers to whom Shield does appeal. Since it debuted in 2015 Shield has gained a good following of people I like to call file hoarders. They have big collections of files -- namely TV shows and movies downloaded from various no-questions-asked corners of the Internet, usually ripped by somebody from DVD or Blu-ray -- that they want to play on a TV over a home network. The powerful Shield does a superb job of that, whether via Plex, Kodi, Emby or something else. Of course, it also costs more than many other hoarder-friendly devices.

When they reach for their wallets, most people will bet on another horse: a different streamer or a serious gaming rig like a console or PC, or both. Although it's better than it was a year ago at launch, the expensive Shield still fills too narrow of a niche.

Editors' note, April 25, 2016: This review has been updated since its publication, taking into account updates including Android Marshmallow, which improved stability and added features, as well as new apps and games, and testing of the GeForce Now game-streaming service. Its Value rating was changed from 5 to 6 and its Ecosystem rating was changed from 7 to 8, which increased its overall rating from 6.9 to 7.5.

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Triple Shielded

The Android TV box is the third Nvidia Shield in the PC graphics company's armory. All three are Android devices with access to the Google Play Store's app library. They also get three Nvidia-specific features, namely optimized games and a handful of big titles like Borderlands: The Pre-Sequel and Metal Gear Rising: The Revengeance (here's a partial list); compatibility with GameStream, which lets you stream games running on an Nvidia-equipped PC to screens elsewhere in the house or remotely; and access to Grid, the company's cloud-based game-streaming service.

Allow me to draw tenuous comparisons to three kinds of medieval shields as we run through the family tree.

The first Nvidia Shield, a tiny, duel-friendly buckler in size, was renamed Shield Portable and sells for a whopping $550. It's still available, although this generation is being phased out. Basically a game controller with a touchscreen screen grafted on top, the weird device suffered from a small game library compared with other portables like the PlayStation Vita or Nintendo 3DS .

The second, called the Shield Tablet, is a high-powered, $200 Android tablet that we really like. Our admiration stems from its relative value for the specifications, not from its gaming prowess. It's a classic medium heater shield in terms of popular appeal and screen size.

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The third is the new Nvidia Shield Android TV box. Like a tower shield, or scutum, it's the biggest of its kind, at least in terms of the screens it feeds.

It comes in two varieties, the $200 Shield and the $300 Shield Pro. Both are available in the US and Europe now (Australian availability is not part of the conversation -- sorry!).

The Pro increases onboard storage from 16GB to 500GB. I reviewed the standard Shield, but since the two units are identical aside from storage capacity (and weight, although the other physical dimensions are the same), my observations apply to it as well.

If you're hard-core enough to be considering the Pro, be aware that the upgrade to Android Marshmallow brings with it the ability to replace Shield's internal storage with an SD card or USB device up to 128GB. Unless you're storing numerous files and big games on the device, that's probably enough.

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The box: Is that Dragonglass?

If set-top boxes were graded on aggressive looks alone, the Shield would bash the competition, and perhaps slay a White Walker or two along the way. This slim, angular shard is traced by diagonal ridges, alternating glossy and matte-black finishes, and a razor-sharp sideways green "V" that illuminates when it's on. Best. Power. Indicator. Ever.

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The default orientation is horizontal but you can also set it into an optional matching stand ($30 or £25) to keep it vertical. On the top is a touch-sensitive power button I accidentally hit more than once, and the slim front face sports an infrared (IR) sensor so the Shield can work with most universal remote controls.

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The back panel lines up the Shield's prodigious array of ports, bookended by a cooling vent. Because Nvidia.

The controller: Feature-packed but too bulky

A single Shield controller ships with the device. Chunkier than other controllers, especially those of the PlayStation 3 and 4, it feels significantly heavier in the hand.

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It's decent, but I definitely prefer the Xbox and PlayStation controllers, mainly because they feel much lighter; their longer grips felt more natural, especially over extended periods of gaming. Happily, the Shield worked with a variety of Bluetooth controllers (including Amazon's) and the wired Xbox 360 controller.

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The Shield controller out-features most, however. It offers a volume control, a microphone for voice search and a headphone jack for private listening, a la Roku 3. Unlike the Roku, volume on the Shield also controls the HDMI port's output level, so you can control the TV or AV receiver volume, too. It's also worth noting that, like the Fire TV and Apple TV, the Shield can pair with Bluetooth headphones like the Sennheiser Momentums I tried.

One-handed remote: A $50 option (ouch)

Unlike pretty much every other streaming box, the Shield doesn't ship with a simple remote. Sure you can use the controller to do everything, but it's impossible to use with one hand. You can also use the Android TV Remote Control app, which is great (especially for entering text) but requires your phone or tablet.

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The optional clicker costs a whopping $50 or £40. It's nice enough, as these things go, with a slick, touch-sensitive slider for volume control. I do wish the home key were more prominent and the voice-search button was less so. Dedicated controls for play/pause, rewind and fast-forward would be welcome too, but the cursor key works fine for those functions.

Just like the controller, the remote offers voice search via a built-in mic and a headphone jack for private listening. It's also rechargeable, and had a tendency to go dead more often than I expected.

My main complaint about the remote and the game controller is that they had a tendency to become disconnected after awhile, so I had to wait for a second or two (or sometimes longer) before they could properly command the Shield. I'm guessing the idea is to save battery life, but it's an annoying issue in a living-room device.

High-end hardware

Nvidia justifies the Shield's high price with better specifications than any streaming box out there.

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It starts with Nvidia's latest Tegra X1 processor, 3GB of RAM and a 265-core Maxwell-generation GPU, for "raw performance" that's 3x better than the 2015 Apple TV, 4x better than the 2015 Fire TV, and 10x better then the Roku 4, according to Nvidia. Those numbers deserve a healthy dose of salt, but you get the idea.

The box supports 4K video output with the potential for HDR. It has both fast 802.11ac dual-band Wi-Fi and an actual Ethernet jack -- Gigabit, of course. For expansion, it has two USB 3.0 ports, a Micro-USB port and a microSD card slot that supports cards up to 128GB in size, to augment the built-in 16GB of storage on the standard Shield.

As I mentioned above, one of the chief features of the latest operating system update, Marshmallow, is to allow SD cards and USB devices up to 128GB to serve as internal storage. This feature replaces the clunky, buggy "Move apps to SD card" function. I upgraded a couple different Shield models, one with a 64GB SD card and another with a 128GB USB 3.0 stick, and they worked fine. Nvidia's support forum has a detailed walkthrough.

The Shield is easier to accessorize than any streaming box I've tested. The USB ports work with external USB hard drives and USB sticks for media playback. I connected a 2TB drive filled with photos and videos, including lots of 4K material, and it worked great once I installed the VLC Player app for playback (the default Photos & Videos app is terrible).

In addition to game controllers and headphones, I was also able to successfully connect Bluetooth keyboards from Logitech and Samsung, and they worked in numerous apps. Although I didn't test it, Shield is also said to work with the HD HomeRun TV tuner, allowing live TV and DVR functionality from over-the-air broadcasts.