I'd wait for SA's part of the tournament to be over before making any statements on him. And it's not exactly fair either. Even Inzamam was **** poor in World Cups (except for that solitary knock in the 92' WC), yet he was a very good servant for his team. Give Amla his time to prove himself.
Widely regarded as an impact player. But was a failure in world cups barring 92!
In ODIs, Amla indeed may not have the image of an impact player yet. Can this be changed? surely yes.
Kohli has been breaking Viv's record in fastest ODI runs. In turn, Amla is breaking those Kohli records.
Kohli admittedly has more flair and more gears. SRT and Ponting were great, but many would choose Ponting for his style of play which was more aggressive.