It was just like how we groaned after Shilpa or Suku left. If KSG left for good, this "groaning" is ought to be much "louder" because he has been here since the start. Just like how Shilpa is still seen as the original Riddhima, KSG is seen as the original Armaan, and since he never got changed - the only Armaan.
I think AR's love deserves to be completed - doesn't matter what actors portraying it. But I love KaJen, so I want them to portray the characters. That's just my opinion. :)