I have a few questions about gates of the forge.

-What races is it good for?
-What kinda ac numbers are we looking to have for it to be really affective?
-Does it help with vulns or say energy type weapons or is it more like a phys resist?
-Is it even a good legacy choice for the right race?
-And does dex have a factor in it say like arial having 25 dex with their ac bonus or is it just armor ac bonus?

I thank you for your answers, and I want to hear all sides of it good and bad.

ty :D