http://dbd.game/killswitch
Nerfed Thana Numbers
With Thana's nerf, my previous posts compiling the perk's effect by itself, and with Dying Light became obsolete. Rather than focus purely on gens, I'm going to detail its effect on sabo-ing and totem cleansing as well.
Gen Repairs
0 survs injured - 90
1 - 91.84
2 - 93.75
3 - 95.74
4 - 112.5
Sabo-ing
0 survs injured - 3 seconds
1 - 3.06
2 - 3.125
3 - 3.19
4 - 3.75
Totem Cleansing
0 survs injured - 14
1 - 14.29
2 - 14.58
3 - 14.89
4 - 17.5
Conclusion
It is an absolute waste of a perk slot. I don't care if you're Legion, I main Legion, and I'm telling you, it's a waste. Don't use this perk. All it takes is a single medkit, an extremely common item, or CoH, a very common perk in today's meta, to delete this perk from existence.
If you play Legion or Plague, Blood Echo is right there. It'll give you a lot more value than this perk ever will. Want slowdown? Eruption, CoB, Jolt/Surge, Pain Res, etc are over there.
Survivors, this perk isn't doing jack. Don't be fooled by the red bar. Saying this because my solo queue teammates like panic healing when they see Thana. Trust me. You'll waste more time healing than this perk will ever do.