For the cost and small portable size, the ShutleXpress was a no brainer for me compared to the more expensive Pro. I initially had issues getting the jog and shuttle to scroll and stop smoothly in Final Cut Pro (apparently the keystrokes assigned to the jog and shuttle get queued up as you turn one of these dials). Just when I was at a complete loss, I discovered the 'Apple Final Cut Pro Capture' setting solved the issue. Don't know why, it works though!
As I have solved the issues getting the Shuttle to work with Final Cut Pro, including disabling some keyboard shortcuts in OS X, I am giving it 5 stars as it's extremely useful. To be able to have one hand on the mouse whilst the other scrolling and using the five buttons on the ShuttleXpress is such a time saver.