I am sorry, but I don't agree. He has been occasionally very good, but when he was driving really good cars in Suzuka, he managed to get a great result just once, and that was last year. For example, Barrichello beat him in 2009, McLaren was faster than Ferrari in 2010 at Suzuka and yet he was behind Alonso both in Q and in the race, also he was slower than Hamilton in Q but Lewis had a 5 place penalty because of gearbox change. Sato also outqualified him in 2004, when BAR was the second best car. I am not saying that he is not driving well there, but an expert would certainly need to do more.
yeah, it's true Mclaren was faster than Ferrari in Suzuka but Jenson qualified on hard tires while everybody else was on softs.
Button, with harder tires, was 2 tenths slower than Lewis with soft ones. Quite good result if you ask me tbh.
But I also agree he isn't exactly a specialist in this track. He's definitely good but I wouldn't go that far to put him anywhere near drivers like Berger(who beaten many of his team mates in Suzuka, including Senna and Alesi), A.Senna and M.Schumacher
Jenson outqualified and was outqualified in Suzuka by Sato, Rubens and Lewis, so he's good but not dominant to be pedant.