Any attachable keyboard on the iPad will be the same. When the keyboard hides itself (on the home screen, or any other screen without the keyboard input selected), you are left with a keyboard covering 25% of your real estate. However this review seemed to note that it is possible to click through the keyboard, which is a good thing in that regard.
What he is saying is, if you have this plastic keyboard attached to your iPad, then you are stuck in software-keyboard mode. If you dismiss the software keyboard, then you have no access to the UI now displayed on the bottom half of the screen, without pulling off the plastic keyboard.
I tend to agree -- there are only a very few iPad apps that are designed to be used 100% of the time with the soft keyboard displayed. Even in mail, for example, you switch back and forth between browse and edit mode.
