Like everyone else has said, damage utility is the best utility in that it's the one that has the most consistent returns and the tangible results to prove it. As great as extra healing and defense are, the problem is that fights are scripted in not just the rotation but also the damage as well. You know how hard things are going to hit once you get the flow done. For example, the only gcd healing I have to do in Emerald is the orbs for 2/2/2/2. Everything else I can just gcd healing because the damage is that predictable and spread out. Any extra mitigation outside of reprisal and the range utility is superfluous at best. Only in certain fights like UCOB golden bahamut or TEA perfect alex is more defensive utility needed.