In laptop mode, the ClamCase Pro feels great, for the most part. The keys were sometimes a little sticky, but the comfy layout and bonus row of iOS-specific buttons above the number keys felt great. It's deceptively just like using a real laptop: so much so, that my finger kept wandering to the space in the middle of the aluminum palmrest, expecting a trackpad. No such luck, of course: iPads don't support trackpads. It's a cruel tease, having that spare space on the ClamCase Pro, but what can you do?
The top-heavy nature of the ClamCase also takes some getting used to. Even if it looks like a laptop, it's not centered like one. Bend that adjustable-angle top too far back and your iPad will swan-dive backward off your lap. And the bendable hinge, while sturdy, wobbled when tapping or touching the iPad while working; I wish the hinge were a little stiffer.
You can access most ports while the iPad Air is in the ClamCase Pro; there's a Lightning cable hole, grilles for the speakers, volume button pass-throughs, and even a rear camera hole. But the hole for the headphone jack is too narrow for many larger headphone plugs; it works with Apple's EarPods, but it didn't work with my other headphones. That's a drawback. The case charges via Micro-USB (cable included) and lasts months on a charge; I wasn't able to test that, but I haven't needed to charge it once yet, either. The keyboard case automatically goes into sleep mode when not in use for a few minutes, too, to conserve power: to activate again while in "laptop" mode, I just needed to press a key until the Bluetooth icon blinked back to life.
The ClamCase Pro weighs 1.2 pounds (545 grams), which along with your 1-pound iPad Air will add up to a 2.2-pound, 0.75-inch-thick object in your bag. That pushes into other netbook or hybrid-laptop territory, and certainly makes the Air seem less airy when popped in. The previous iPad 2/3/4 ClamCase Pro weighed 1.5 pounds, or nearly 3 pounds with iPad inside, so this one's definitely an improvement.
Despite some gripes, the ClamCase Pro for iPad Air is one of the best, versatile, sturdy, and functional iPad Air keyboard cases I've ever seen. It's beautiful and it's fun to use. But it's expensive, and it's a little heavy and bulky. I'm not sure if there's a full-fledged keyboard case I like more at the moment, but then again, I prefer popping the Air into a separate standalone keyboard. Your tastes may vary.