You didn't waste your money, the Shuttle Express is super great. I use mine in MediaEngine with great effect. I mapped the inner wheel to up/down arrow, and the #2 and #4 button to left and right arrow. The center button to enter, the far right to 'Browse' and the far left to escape. The jog-dial is mapped to send 'forward' or rewind' keystrokes at varying speeds, and I'm happy as the proverbial clam.
I'm playing with Centrafuse, and I think I might need to remap the keys that CF expects to see because I haven't figured out how to do special-move combos yet (like Ctl-Alt-J and whatnot).