(my experience, my opinion, we can argue and I might change my opinion)
I currently lead a 1900 MMR rated RBG, besides that I read up a lot on forums such as AJ - MMO and the regualar WoW forums. So you have a little bit of an idea on what my background is.
In the current state of RBG Death Knights do the most damage overall. Warlocks have the most killingblows because of their Chaosbolts. Monk healers have a spot as group healers and they are good at it. Mages just bring a ton of utility. Shadowpriests bring lifeswap and massdispell, boomkins bring mass silence and a ton of AoE damage. The list goes on. But what do hunters bring?
We bring our beastmastery specc which has good damage on demand. In the group fights I bring quite some effective nuke damage, which can be called upon instantly. I found out that the CC's my pet get on him is minimal and mostly of the time when I need my pet I can pop BW or Bullheaded to get that extra nuke damage going or RoS. But after my nuke damage, my damage is just shit.
My traps are usually broken by Death Knights or any other AoE CC. It just feels weak and usually is.
Now that is where survival comes in. When I read about the changes on Serpent Sting I decided to specc it during certain maps, basicly all maps that do not have Notes to defend. AB-Gilneas-EotS are these three maps where BM is mandatory for any setup you run with. cause of that extra trinket and the immense survivalbility and solo-ability. Ninja capping was never easier.
So the first WSG we entered the groupfight. I just went absolutly nuts with my Multi shot and I was topping the damage charts with atleast 3-5million more damage done every time. I was suprised.
The question is tho? Is it effective enough to actually kill stuff.
The answer: Yes and No.
We use a Boomkin and Death Knight together with a Mage for massgrips, AOE silence and RoF. The whole group is together, CC'd and dies. My role as Survival hunter is huge there. My damage is immense and the singletarget DPS I can do after my AOE ROOT TRAP procs is high!
Besides the massgrips, our Death Knight brings a ton of AOE damage together with the Boomkin. We keep the AOE pressure and as soon as something is low (70-60%) we kill it.
I'm even suprised how good survival is in 1v1. I have to outlast their damage for the first 5-10 sec. Which is done easily as Hunter, then the procs of Explosive Shot comes in and shit dies.
I have yet to find a pet that goes well with all this. Using crane now for extra CC, but it breaks too easy.
So all fellow hunter, we do have a spot in RBG!