Basics
The Ultrathin Keyboard Cover is the result of your typical iPad keyboard gettin' busy with one of Apple's Smart Covers. At the top of the keyboard is a magnetic bar that allows you to attach it to an iPad 2 or 3, then flip it over and use it as a protective cover while traveling.
When you're ready to get to work, yank off the keyboard and drop your iPad into the "prop slot" (is there a more official name for that?) in either portrait or landscape mode on its left side, since volume and slider controls are on the right. For bonus points, there are even magnets in the slot to ensure the iPad stays snug if you use it in landscape.
Construction
The keyboard itself is really good and *really* slim; as in, if you like large, bulky keyboards with lots of key travel and noise, this is the polar opposite. Like most iPad keyboards that shed some weight to fit the 9.7-inch form factor, the Ultrathin Keyboard Cover has five rows, and the individual keys are slightly smaller than their on-screen equivalents. I don't find it very tough to adjust from Apple's iMac and MacBook Air keyboards, though, since I've been getting used to touch typing on the iPad's display.
The keys themselves feel solid for this class of keyboard. They have a very short amount of travel, which I love. When the setup is closed, it feels really strong and solid, much like an 11-inch MacBook Air feels when closed. There are thin rubber pads on the outer four corners to ensure its keys don't mark up or even touch the iPad's display.
I usually toss my iPad into a dedicated, padded sleeve in my Booq backpack or Tom Bihn Ristretto. But with the solid feel of this setup when closed, I would feel confident mixing my iPad into a main compartment filled with books and other items.
Keyboard
As usual with this form factor, Logitech had to make choices on how to resize certain keys in order to fit everything. For example, there are Function, Control, Option, and Command keys (since they all have their uses, even in iOS) on the left of the space bar, and Command and Option keys on the right. But the Command key is about half its size, and the Option key is also a little slim, as is the Delete key on the right of the number bar. If you're the type who hates to add to your muscle memory, this could be an annoying hurdle to overcome. But if you like staying nimble, be patient and you'll probably get comfortable hitting everything you need.
Now, it's worth pointing out that iOS supports many of OS X's text manipulation shortcuts when you use a physical keyboard. Option + left/right lets you skip back and forward an entire word. Toss Shift in there and now you're selecting whole words while skipping around. Option + up/down will skip you to the top and bottom of the current paragraph, and again, including Shift will let you select the entire paragraph. Command + left/right arrows will skip you to the front or end of the current line, while Command + up/down arrows will skip you to the beginning and end of the entire document.
One thing I love about iPad keyboards is that the manufacturer usually tosses in a few shortcuts that make it easier to get around in iOS and, more importantly, do much of this text manipulation. This is especially useful for people who don't know about the aforementioned shortcuts or just find them a little complicated to remember.
Logitech made every key in the number row, including the dash key, math symbols, and even Delete, do double duty with assistance from the Function key. For example, if you hold Function and hit 6, 7, and 8, you'll be able to cut, copy, and paste selected text. But when it comes to selecting text in the first place, Logitech added new options to the 4 and 5 keys on this Ultrathin Keyboard Cover that simplify the Option + Shift + left/right arrow shortcut for selection text before and after the current cursor position. Despite having an extra row of keys, Logitech's precursor to this model, the Keyboard Case, doesn't have these text selection shortcuts.
Comparison
Speaking of the Ultrathin Keyboard Cover's big brother, I have two competitors to compare this against. The first is the Keyboard Case, which is essentially an iPad keyboard inset in a metal enclosure, so you place the iPad display-down and fit it on top of the keyboard for travel. The other keyboard I have is the ZAGGfolio, a portfolio case that wraps an iPad and keyboard together in a traditional notebook approach. The Zaggfolio's keyboard is a rebranded version of Logitech's, by the way, so it's basically the same keyboard in the Keyboard Case.
The main advantage I see to the Keyboard Case (and the Zaggfolio's keyboard) is that the special function keys are split out into their own row, the 6th row I mentioned earlier. If you don't want to hit a second key (Function) to make those features work, as is required on the Ultrathin Keyboard Cover, I can see the Keyboard Case being appealing. I've been writing so long, though, that the text manipulation shortcuts are second nature and I don't use the iOS shortcuts all that much. But when I do need them, I don't mind using the Function key to trigger things like iOS's system-wide search pane or media controls.
When it comes to the pack-up-and-go factor, the Ultrathin Keyboard Cover really pulls ahead. It's actually a little fun to pull out the iPad, move it towards the top of the keyboard, and watch the magnetic magic happen. It's just plain faster.
Comparing the Ultrathin Keyboard Cover to a Zaggfolio or any portfolio-style case like it is a different story, because the entirety of this comparison probably hinges on whether you actually want a portfolio case to encapsulate your iPad and a keyboard.
The Zaggfolio was the first iPad keyboard I ever bought, and I quickly realized that I am not this type of customer. I like to hold my iPad by itself, usually curled up on the couch or in a coffee shop chair, reading or playing a game. No matter how easy a portfolio case makes it to remove or detach an iPad, I've never liked that barrier to entry.
But if you want the protection or other perks of a portfolio case, the Ultrathin Keyboard Cover may not be for you. It's about the thinnest and most minimal iPad-specific keyboard I've ever seen, and when you boil it all down, it only protects the iPad's display while in transit and nothing more, just like Apple's Smart Cover.
Another important point to consider in all three keyboards I've mentioned is that they do not allow you to adjust the iPad's viewing angle. Some portfolio cases, like the Incase Book Jacket, try to solve this problem to some extent, but I generally don't find the single-angle prop slot to be an issue.
Conclusion
The iPad is the epitome of mobile computing, and the Logitech Ultrathin Keyboard Cover is its greatest physical keyboard counterpart yet. I used it to write this entire review, thanks to Writing Kit and its excellent built-in browser and citation tools. If you want an easily detachable keyboard for powering through serious typing on your iPad, I definitely recommend you give it a look.
Addendum
Q: WyldKard asked on Twitter: "How well does the keyboard work on your lap in various positions? Or is it best used on a table only?"
A: It works surprisingly well. In fact you could even say it really turns the iPad into a "lap" "top", as in: a computing device you can use in your lap but will not set your lap on fire. The magnetic prop slot plays a big part in that, since it keeps the iPad firmly in place while in landscape orientation. I find I need to use it with two feet on the ground, though; the setup is just not wide enough to be propped very well while sitting cross-legged.
