Just an odd but quick question:
How much should it turn to the right as I have just had a quick play (without plug-in it in) and it seems to turn a lot more to the left and not to the right!
Is this normal?
Are you positive about that? The sensor (an optical device) is symmetric.
Try using the other hand. It could be just a matter of user perception. Note the 3D mice should be used with your non-dexterous hand. If you're right-handed, the left hand should hold the 3D mouse (for navigation) and the right hand holds the normal mouse (for point-and-click selection/activation).
From the initial position it does move more left.
I just tested it in Google Earth: Depending on the force applied spinning left gets faster or slower (more physical movement) but right just stops and is only one speed + force.