If I run with my guildy on the Alderan Warzone who is a vanguard and he shields me we dominate.
If I run huttball I am pretty much useless and get cc'd heavy/annihilated.
If I heal random people I waste heals because they are too squishy, and it usually dries up my ammo and I get burned down quickly.
I can heal great at a distance, but I run out of ammo quick, even with supercharge cells active.
Mobility is an issue and even with cryo grenade, pushbacks, and interrupts I feel like I have a hard time escaping.
Healing rarely can keep up with two dmg dealers.
Only 70% pushback reduction was a terrible idea when all my heals on self require cast bars.
Overall I'd say if you are running a premade, healing is 8/10.
If you are running alone, with the buggy frames, healing is 4/10.
Survivability with a vanguard guarding you, 8/10.
Survivability alone, 3/10.