Treek does a better job than the other healers. The CZ-198 SM flashpoints are soloable, but Core Meltdown is way easier with Treek. At least she does stand out of range healing herself only, like Fishboy (Gus) or Doc. Her AI actually seems better.
Thanks for the advice on a completely unrelated topic that no one mentioned. But to answer you, I'm solo'ing that as DPS sage with Nadia, there's no need for a heal pet on it.
And no, Treek does not do a better job when there's AOE involved and she doesnt have to move to get in range of you, like on the boss I actually brought up. She didnt heal me once during the entire fight and she couldnt even keep herself alive. Nadia. despite being DD, was actually better because she follows the boss, whereas Treek will stay in the same spot the entire time and eat every AOE.