It's quite amazing how Kallis has gone from underrated to overrated in the span of a series. Look, Kallis is a fantastic cricketer; an all-time great.
His batting is in the league of Sachin, Ponting, Dravid and Lara, certainly. However, I would say he is inferior to them, still. With regards to Ponting; one has to remember that Kallis has scored a ****load against B/Z where Ponting has had very few matches against them.
Without minnows, the difference between them is 2 runs on average in favour of Kallis and 15 points on SR in favour of Ponting. I'd say that more or less puts them equal in terms of crude output. I say that because I read Marcuss arguing how Kallis simply scored more runs and was hence better. That's like saying Yousuf is better than Steve Waugh.
But that doesn't scratch the surface IMO because it says little about the quality of the runs scored. I'd always thought Kallis generally scored runs in easier situations/against easier attacks than Ponting but I decided to see if that is the case. Since they're both practically the same age, have played the same amount, debuted the same year and even peaked during the same decade against most the same attacks I decided to look at their records since 1995 - the year they debuted. I have ranked the best bowling attacks from top to bottom and shown who has done better against them.
The top 5 attacks during their time were Australia, S.Africa, Sri Lanka, England and Pakistan. Against them Kallis averages 44.87 @ 44; Ponting averages 52.22 @ 61. Furthermore, Ponting averages above 50 away and at home against all of them bar England (42 and 44). Kallis on the other hand averages in the 30s against both SL and Aus in S.Africa. He averages in the 20s against England in England and in the 30s against SL in SL. At home, he averages above 43 only against Pakistan.
Of course Ponting doesn't face Australia and Kallis doesn't face S.Africa. However, Ponting has a fantastic record against S.Africa and Kallis has a mediocre record against Australia. Where Kallis catches up overall is against the bottom 5 attacks. Not that Ponting does poorly; Kallis just made merry to a greater extent.
Against the bottom 5 attacks Kallis averages 76.74 @ 46; Ponting averages 55.35 @ 58. Against these teams Ponting averages 60+ in every country bar India where he averages in the 20s (note: he had 1 inning in Zimbabwe where he made 31). Kallis too has a fantastic record where he averages above 50 against everyone home and away (note: he had 3 innings in Bangladesh where he averaged 33).
All this is not to point out that Kallis hasn't played quality innings. But on the whole I'd argue much less than Ponting has against the best attacks, home and away.
When I was looking up their records I was very impressed by Kallis' 3rd/4th innings average. With a bit more scrutiny, however, I was a bit disappointed. Kallis has really played for the red ink there. He really piled on the runs in draws that were going nowhere or innings where S.Africa were obviously going to declare they were so ahead. I invite you to look at his 100s in draws and analyse them for yourself. It goes to show you that sometimes perceptions are correct (i.e. Kallis being seemingly selfish) and I get the impression of Kallis being a cricketer who certainly knew his numbers and played for them. I know innings where the likes of Ponting, Lara or Sachin once got to 100s and then let loose for the sake of their team whereas I can recall very few for Kallis.
On the whole, I like that Kallis wasn't battered in this poll; I think he deserves to be thought of alongside the best batsmen of his day. But he was not Ponting's equal, anymore than Barrington was Sobers' IMO- and I actually think the latter pair have more of a debate.