I use Perfect Keyboard (the free cheapskate version) and it's very good. Customizable key size and spacing, good prediction and user dictionary. Lots of features/options plus more if you buy the full version.
It also has a landscape option where you can choose a layout like the Thumb Keyboard in the video above.
I also like that there are symbols marked on the keys as long press functions, saving the need to enter a symbols screen or sub menu, although they are also available. Also has smiley menu on long press of Enter.
Oh, also if you swipe up on the spacebar, the keyboard shifts up to provide arrow keys on the bottom row. Swipe down again to hide. This was actually my reason for originally installing it.
I might try the trial of swiftkey to see what the fuss is about, but if I don't like it I will definitely revert to Perfect Keyboard.
