If you like the idea of a spellsword, try Blue Mage. That's basically what most people expected/hoped for Red Mage to be.

Red Mage favors its magical side far more than its extremely underdeveloped melee side. The job's greatest strength is easily its self-sustainability. Red Mage does not really fill any niche in Endgame right now, but it's a fairly powerful solo job when geared properly. Though, to be honest, it's probably a lot easier and a lot cheaper to solo things on Dancer now.

Essentially, it's a job in limbo. If you like being a self-sustainable pure-mage, it's definitely worth a whirl. If you like swinging swords while casting spells, you're really much better off with BLU.