Ok I've thought about this long and hard. Finally after getting all 3 healing classes to 50 i have found some things to be easier and harder on some classes. First to start out PVP opposed to PVE they are both different so you can't just say this is good and that class is bad. No, they have their own strengths and weaknesses. I'm going to talk from perspective of PVP healing only.
Inquisitor/Sage
I'm going to be saying things i like and dislike, the give and take that BW gave to healers. So the thing i like about inquisitor/sage healing is it is very stable with it's heals. Usually all you need to do is the heal over time to get a critical then big heal and depending on how low the healing target is, maybe put a shield on them or healing trance/inveterate. Unlike any other class this one has something called "recklessness" which makes the next ability effectiveness increase which usually means it hits a critical; and usually that crit for me is around 4.8k. Basically the class is just consistent with the heals unless the healer gets interrupted. This is one of the take's; While the heals are spot on they are ALL channeled with the exception of the cleanse and small heal over time. Now i've seen games where i've never been interrupted and come out with 400k and I've seen games where i have been interrupted and barely made it out with 250k. Now the sage/inquis AOE heal is amazing compared to the other classes AOE's which i spam as often as i can if my force is high enough. A downfall is even in full war hero they are extremely easy to kill because of their armor rating's. This is where i am extremely bias because i know how easy it is to kill a sage/inquis heal from the perspective of commando DPS. Their armor rating is atrocious around 2.8k or so in full battlemaster. Outcome in my opinion 8.2/10 for the heals, if not for the heals it would be a much lower rating because of their inability to move and take hits.
Commando/Mercenary
Next is the trooper, my main character. Although i am primarily DPS i have healed in pvp. I find that it is fun and easy to heal at times. Now the nice thing about the commando healing is that it can auto heal itself for 1 heal if used with reserve powercell and tech override. This is extremely useful especially if Bacta Infusion is up because that's a free and instant heal too. Now the thing i do not like is that as like the sage/inquisitor healing you are immobile most of the time UNLESS hammer shot is used but that heals for maybe 1% every second. The worse part about it is if you use it the green light comes out too as most people have seen already, i'm not sure if it's me but when marauders see that thing they take off like a bat out of hell to kill the source, from my experience. Another ability is call Trauma probe, it's excellent for self healing if an enemy is attacking you and you are trying to save a teammate, just have the probe on yourself and heal your ally. Now it doesn't do too much but it mitigates damage by healing you each time you're hit. Another thing to keep you alive is the trooper's heavy armor, unlike the sage/inquis light 2800 the armor rating is around 4800 or so for trooper giving a fairly big advantage to troopers. For their survivability i give the trooper an 8.1, not higher than the sage/inquis because they can heal for a higher amount and faster.
Scoundrel/Operative
Last but certainly not least the scoundrel/operative healing class. Now the scoundrel class isn't just "oh spam the free thing" as i ignorantly thought it was. Now in my opinion scoundrel healing is the hardest but most rewarding healing class. The hard thing is keeping up upperhand/ tactical advantage, i don't know about others but i had to break the habbit of spamming upperhand until it was diminished. Emergency medpac takes actual skill to use and you gotta know when to use it and when not to which i just learned today. Unlike the trooper and sage healing AOE the scoundrel's is an overtime heal and it costs 27 energy which is 27% if you don't have the 5 max increased set bonus. Most of the heals that don't require upperhand are expensive and this is where it gets a little tricky. A big part of the healing is to not drop under 50% or your energy will take forever to rise back up. The one thing that i like is that it's challenging and by that i mean it's not easy to heal unlike sage healing. I'm not talking about surviving here but actual healing, it takes understanding of the class to apply the correct heals needed. The thing is upperhand is key in playing the class, and to keep upperhand up you must have the overtime heal (Slow-release medpac) active and use diagnostic scan and underworld medicine when needed. The other good thing is that it's not light but medium armor which granted isn't much better than light but it is betetr. Also they can use 1 type of shield no other class has called "dodge" on the republic side whcih increases shield chance by 200% making them nearly invincible for 4 seconds. (sorry i don't know what it's called on imp side!) For the understanding of the healing needed, actual heals and survivabilty i give the scoundrel a 9.4 effectiveness.
Now I'm writing this because these are the healing classes that i find to be better or worse and to see if people agree with me or disagree. Please comment below and let me know why or why not you might disagree!!!
Server-Jedi covenant
Imperial----Pyrodraco-Sorcerer
Republic---Füsrodah-Commando
Republic---Fokrahdiin-Scoundrel