to my mind the Challenger Loadingscreenborder doesnt differ much from the gold one. I think the old Master/Challengerborders were way more special than the new ones. I mean u put alot of efford in order to get to challenger and the reward is not realy worth the efford. At least it feels likethat..
I hope Riot gonna revert the changes, or at least buff the Challenger/Grandmaster-Loadingscreen border soonish. Screenshot in Description.....