In almost all cases, parsing in the data flow pefroms (sic) better than parsing at the source, if not at the same performance level.
Sam, I'm sorry, this sentence doesn't make any sense to me. If something performs better, say so. But adding the qualifier "if not at the same performance level" negates any meaning.
I'm not saying your methodology is wrong - in fact, in terms of human effort, it's vastly superior IMO, but I can't work out whether you've added the qualifier beacuse the total processing time is increased (is it?) or for some other reason.