I still think Conserve MP(lvl 40 WHM/BLM learns it) is greater than Auto-Refresh(lvl 50 WHM/SMN learns it).

Mainly becuase many times i see Haste(40MP) be cut down in mp cost by half, and although its somewhat random, it does make everything more MP Efficient and seems to be better than 1 MP per 3 second tick when usually a BRD or RDM can do that...