I believe it got removed because the new policy is to not discuss use of Action Replay codes. Google will provide you with the information you need.
With SRing you can already know the Nature/Gender/Ability, so you can have that guaranteed, but you need to reset for IVs. With mass hatching, you just take a bunch of eggs and hatch them, not knowing Nature/Gender/Ability, and having set IVs. SRing can be useful if you really need a certain Gender/Ability (such as Gallade, or Solid Rock Rhyperior), but otherwise I think it's just up to personal preference. With mass hatching, you do get more "spitbacks", so it can make you feel like you've accomplished something at the end of the day.