Better battery life or faster charging?
Apple advertises up to 10 hours of use on a single charge, which is mostly standard for a device this size, though we don't know much about the size of the battery pack that's actually inside it and haven't tested its claims for ourselves. The Kindle Fire HDX 8.9 and the Nokia Lumia 2520 both tout an hour more, with the latter including fast-charging abilities, though its separate ports for MicroUSB 3.0 and microHDMI will ultimately cause some cord-tangle you won't want to contend with.
Photo taking -- with your tablet
Not that we're advocating that you snap photos with your iPad (or any other tablet for that matter), but Apple also announced that the Air includes an improved 5MP rear-facing camera, in addition to a 1.2MP front-facing FaceTime camera and dual microphones. The iPad's camera features sound great on paper, and though the Kindle Fire HDX 8.9 sounds impressive with its 8MP camera sensor, the Lumia 2520 is likely to beat out the bunch. Its 6.7MP rear-facing camera with optical image stabilization, 2MP front-facing camera, and four microphones could ensure that it's likely to take some of the best tablet photos in the industry, especially if it takes after the photo-taking capabilities of its Lumia camera phones.
iTunes, Amazon App Store, or Windows Store?
Apple's ecosystem is both one of its strengths and its weaknesses: it's content and app offerings trump what most of what the others offer. As long as you have an Apple TV in your home, it's a cinch to take a video or music playlist from the iPad Air and play it over your home entertainment system with AirPlay. However, its closed ecosystem may prove troublesome if you're not the type to be specifically devoted to one platform, and your experience might feel a little disjointed if you don't have an Apple TV, iPhone, or PC loaded up with iTunes.
The Amazon ecosystem, on the other hand, feels more inclusive -- the type of platform where anyone, from any background can join in as long as they have an Amazon account. You can watch movies and television shows and listen to any music you've purchased or stored up in the cloud on virtually anything -- Amazon has clients for consoles, computers, tablets, and set-top boxes. It also comes with a free month of Amazon Prime, which gives you free two-day shipping, a library of free e-books to rent, and free video content to watch. For the technically inept, there is also Mayday, which offers instant, free video chat to an Amazon customer service representative. It's Achilles' heel is the fact that it runs a forked version of Android that doesn't work with the same library of applications as the Google Play Store. The Amazon Marketplace may feel limited in its application offerings, especially if you're looking for a tablet that works as more than just an entertainment consumption device.
Nokia's Lumia 2520 and Microsoft's Surface 2 are good productivity tools, since they run Windows 8.1 RT. With access to Office and covers that have built-in keyboards (sold separately), plus the ability to "snap" two applications on the screen at once, they're good choices for getting work done. You may find Microsoft's Windows Store offerings are also quite slim compared to the Apple App Store.
The iPad Air may be the biggest model refresh since the release of the iPad 2 back in 2011, and it continues to lean on Apple's strengths: beautiful design, a wide array of apps and content, and ease-of-use. But it's competing in a different market than even a few years ago, and it's up against an increasing number of large-tablet experiences. We'll have a full evaluation of the device and our official rating in the coming weeks.