My new favourite keyboard: Kensington
Logitech used to make my keyboard of choice, because it offered a 'proper' non-chiclet keyboard (80%-size) and a protective cover as well as working well. Not any longer.
As of September 2012 my favourite is from Kensington: cheaper (by 15%), has a better keyboard layout, provides a reliable prop-up screen system as well as a cover (nicely designed), and a strap to keep it shut.
It even has a holder for my stylus. Kensington's does have chiclet keys, but so does the new Logitech's, and it seems as comfortable as the standard keyboard for the amount of typing I actually do on the iPad-3. A major advantage it does have over the Logitech version is that system-suspension is not next to backspace. I am no longer continually shutting off my iPad when I try to delete texts.
What's not so good
What's not to like? To change your keyboard layout you have to call up the onscreen keyboard, whereas the Logitech has a separate key.
I also miss the cut and paste keys at the top of the Logitech keyboad, but since I can use command-x, command-c and command-v (as on the Mac), I can live with that.
It isn't quite as comfortable on your lap as it should be (because the iPad-3 weighs more than the keyboard).
I don't know whether it automatically shuts off or on (nor with the new Logitech), but then it never seemed much use except as an advertising gimmick, because we have password protection on our iPads anyway.
If you love Logitech
I recommend the new Logitech keyboard over the old one, if you can stand the switch to chiclet keys, because it now uses iPad's magnets to hold the screen onto the keyboard. My iPad regularly fell off the old keyboard after a slight movement from me.