Well both the Novice and Masters will be throwing the 42lb heavyweight, so there really isn't any difference other than the competition you'll be facing.

Just for reference, most Masters actually throw around the B or even A level, there really is something to old age and craftiness.

Novice will have some first timers who haven't got a clue, but it might also have some studs who throw track or are just natural athletes, but never threw in a Highland Games before. In other words the Novice has no consistency, but the Masters has some pretty tough throwers.