I can only comment from my own experience.
Up to about 120mph a DSG will leave a manual behind. No two ways about it. My 1/4 runs stop after this point so I've not had a chance to top out yet next to a manual. But I'm going to a little place called Germany in 2 weeks.

Round a track the DSG can be considered more as a wife. For my part I am competent at heel/toe and double clutching and left foot braking so I never had a problem in taking a manual car round. In comparison the DSG annoys the life out of me. It always wants a different gear but you do learn to live with it. When that happens it becomes faster and faster and then I think they would be neck and neck. It's all about how comfortable the driver is in the car.
But the big advantage of a DSG on track is if I was to let my missus have a go. No over revs, no burnt clutch etc.
Ultimately though it comes down to personal preference. If you like manual, stick with manual. It's tried and tested and great. If you like automatics however then the DSG is by far the best auto I've driven.