In some ways, it's silly to compare the iPad Air to the Surface Pro. Apple has defiantly kept its iPads separate from its MacBooks, and Microsoft prefers to call the Surface Pro an Ultrabook, not a tablet. As this branding differentiation suggests, whether you want an iPad or a Surface Pro depends a great deal on whether you want a superlative tablet with limited laptop functions or a highly portable laptop with modest tablet functions.
Nonetheless, when it becomes available in November, the 64-GB iPad Air will cost $699, same as the 64-GB Surface Pro. The devices share many functions and occupy similar price brackets, so as dissimilar as they are in certain respects, the iPad Air and Surface Pro are also destined to be compared.
For tablet use, the iPad Air offers superior ergonomics and ecosystem. The Surface Pro is arguably better suited to productivity tasks, and Microsoft's new Type Cover 2 and Touch Cover 2 keyboard covers are quite nice.
But studies suggest many people are content to use third-party keyboards with their iPads, a trend that Apple's free iWork apps can only encourage. Moreover, iPad productivity has as much to do with changing how and when people interact with data and the environment as it does sitting at a desk and typing on a keyboard. So whether the iPad Air or the Surface Pro is better for productivity really comes down to what kind of work you do, whether the iPad/Surface Pro is intended as a companion device or a primary device, and other matters of personal taste.
Against Laptops and Ultrabooks:
Compared to Windows 8.1 Ultrabooks and laptops, the Pro is relatively light and portable. It's rather heavy and thick for a tablet, but it's also more touch-friendly than most traditional clamshell designs (though there are arguable exceptions, such as Lenovo's Yoga). The Surface Pro might be more laptop than tablet, in other words, but if you want convergence, you're more likely to enjoy the Modern UI on a device like the Surface Pro than on a machine with a built-in keyboard.
But there are tradeoffs. Among Windows 8.1 Ultrabooks and laptops priced comparably to the Surface Pro, almost all have larger screens, meaning that users who prioritize desktop productivity over touch apps might be better served by the laptops.
Some potential Surface Pro buyers might also consider Apple's 11-inch MacBook Air. Starting at $999, it's only $100 more than a Surface Pro with Power Cover -- the only Surface Pro configuration that will give users anything close to the 11-inch MacBook Air's nine-hour battery life.
The Surface Pro has a nicer screen than the MacBook Air, as well as laptop-tablet hybridity. It's also slightly lighter. But for those who want a great laptop experience under $1,000, the Air's silky smooth multitouch trackpad, lightning-fast SSD drive and portable ergonomics have always been a compelling package. Now that iWork is included for free and OS X Mavericks makes it easy to sync files and settings between iPads and Macs, laptop-minded buyers might see the Air as more attractive still.