I'm my own best healer, I use Torian now that I got him (at level 35, I went to Taris to do the class quests only) and he's fine for my tank/DPS. I'm fully spec'd into healing as I level for PvP, heroics and FP's. I haven't used Mako since I got Gault. Although, Mako and I were invincible together.
There isn't any one best companion for everyone. It's playstyle dependent.