Ponting's average exploded from 40.51 (before his 144 at Headingley during the 2001 Ashes) to a peak of 60.67 after his century during the 2006 "Amazing Adelaide" test, before it nosedived during the last 6 years of his career back to 51.85 at retirement.
He scored truckloads of runs in his purple patch during 2002-06 before his Kookaburra Graphite bat was banned by the ICC.
Let's be honest here. Ponting scored a lot of his runs in that peak against spuds: India at home, the West Indies, the roads of the UAE. I always felt so few of his runs came in really testing conditions or situations.
Further to that, he had the luxury of batting with the best batsman and playing with the best team of that generation. Smith's career is far from over and thus full judgement on him shouldn't be made, but I can't see in any world where Ponting is better than him. In fact, I put both Waugh and Border clearly ahead of him because of their ability to churn out difficult runs.
If Smith fixes his record against SA and Sri Lanka by the time he retires, which you'd be pretty confident in him doing, it'll be no contest - second to Bradman.