David Kimura PRO said about 3 years ago on Avatars :
  I agree on the response.code. I think that as I was speaking it and typing... It got typed out. 😀

I think that a full solution around this would be to have a background job which gets triggered on create and whenever the email address is updated to do the gravatar_exists? functionality and then update the user to populate a gravatar_url attribute on the user. Then we could check if the user.gravatar_url? and simply return the image_tag with the user.gravatar_url or display the initials.