As I said in my last post, against seam he like any other batsman in the world struggles, against swing however I think he is pretty decent. He has shown this through his test record and multiple test innings against the swinging ball.
Almost all of those innings batting at number 3 were right at the start of his career, batting in a position he didn't even bat in for his province. His relative lack of success could be put down to many things.
I'm willing to hear out your argument that Taylor is only useful in ODI's down the order and T20's (though, how exactly do you argue against his test record?), but i'm still waiting for some sort of evidence or something you have seen consistently to suggest this is the case.