Fun is subjective, compared to the other classes, alot of players (myself included) find the Red Mage an easy to pick up and play type of class. Aside from the Verholy/Verflare (finisher after the sword combo) and Impact a combo skill for Jolt, RDM plays the same at level 64 as at 70, so if a level 64 RDM is boring to you, then I think a level 70 RDM will be boring aswell.