What would be the advantages of using Gecko over Webkit or Chromium/Blink today? Would it run faster? Would it be more compatible? Is it more familiar to Devs?

What would be the advantages of using Gecko over Webkit or Chromium/Blink today? Would it run faster? Would it be more compatible? Is it more familiar to Devs? Is the code base easier to understand? At least with Servo the answer to some of those questions would be a definite yes.