Good Sage brings 10x more to the table then Sent.
Sent = DPS, that's it (and some raid buffs) Sage = DPS, Heals, Bubbles, Rescue, Ranged DPS (This is key)
I play a Marauder alt for good contrast, but overall my Sage is 10x more adaptable, useful, and sought after.
However, KEY IS HAVING FUN, as said before. Pick what you ENJOY.