Hey everyone, here is my opinion about the current support meta of Season 4.
Probably I'll update it in the future because of my bad english, so sorry if I don't explain well.
Both Damba and Corvus are god picks that can bring high heals while giving other benefits like lifesteal and movement speed.
Damba, for example, can offer a great CC Stun to either save yourself or to help your team and can be really rewarding with a great aim for both heals and stuns.
Corvus, in the other side, can offer 15% lifesteal to your marked allies with Grand Design card while also giving them movement speed with Crushing Expectations card.
Furthermore, they can work pretty well on any kind of situations and they're not dependant on maps' hazards.
Both Io and Ying are solid picks that can also bring high heals while offering other benefits like Io.
The thing is I feel that Ying needs some kind of CC to defend herself against most champions, but regardless of that, Ying has one of the most powerful ultimates of the game that can heal everybody while being rewarding too like Damba if you land all heals from Life Exchange talent.
Now, from a Io main, I feel like she's still a very strong support regardless of her S4 nerfs on Luna. This is because of her current builds.
You can go either full heals and auto sustain with Life Link or giving both solid heals and damage reduction with Goddess' Blessing.
Personally, I prefer Goddess because you can keep healing fine while offering DR for the entire team, which is incredibly good when tanking some burst damages like Cassie, Lian, Kinessa, etc. (And you can also keep the auto sustain with Restored Faith card while healing allies).
The only problems that I can see with Io right now is that she struggles with Goddess talent when there are two tanks (point and off) and the off doesn't buy rejuvenate, in those kinds of situations you need to balance your moonlight between everybody to keep some allies fully healed while giving short amounts of heals on others.
She also struggles a lot with caut 3, but her DR can help through to keep alive some allies at low HP while they cover.
And the last problem I see with her too is her performance on the current maps, which are situational.
What I mean with this is that there are some maps that can be awful for her (like Timber Mill and Shattered Desert) while other maps are in fully advantage for her, either for her positions and ult uses (like Jaguar Falls and Frog Isle)
Besides all of that, Io is still a solid support that can be played in all maps too but being aware of what I explained before.
Both Seris and Grover are also solid picks right now.
The problem with them is that I feel like they need some kind of damage reduction on their heals.
This is because of late game caut 3 where their constant AoE heals can be very hard to perform even when having chronos 3.
But besides that, they can still be solid picks where both of their ults can be game changing, especially for Seris now that she is buffed.
Both Furia and Jenos are currently situational picks (especially for Jenos).
This is because they have issues like Jenos' heal and his Luminary nerf and Furia with her Kindle Soul ability where you need to wait three / two seconds to just heal one ally.
And not to mention that they also suffer hardly from late game caut 3.
But besides all of that, they can keep be playing and can also be game changing (especially with Furia's ult, where you can offer both extra damage and movement speed or even with her Solar Blessing talent that can win early game pretty well against caut 1 or mostly caut 2)
Both Grohk and Pip need important buffs to them to overcome the rest of the supports.
This is because people prefer to play them as damage as they're solid picks to go damage, but not main healers.
Pip needs more buffs on his Mega Potion and Combat Medic talents while Grohk on his Spirit's Domain talent.
They also suffer hardly in late game with caut 3, especially Pip.
But even then, you can still play them and do good amount of healing like 150k or more, especially Grohk if you have a good team composition.
I just don't recommend to play them on ranked as healers yet, not until Hi-Rez decides to buff them.