I just took the DAT yesterday, and I thought TS passages are actually quite different from the actual DAT. There are more inference/tone questions on the actual DAT where you will not be able to simply just go to certain paragraphs and look for answers. On the actual RC, there are also questions that seemed more "scattered", and you will not be able to find the answer just with one paragraph. If you have taken the Kaplan midterm, I would say that is closer to the actual thing.
Hope it helps.