In my opinion, if you can't cut it in 3 attempts, chances are you ain't gonna cut it ever and I think thats the approach they use in their thinking process. I am sure there have been a few cases (even few around SDN) where folks did TERRIBLE in the first 3 attempts and just murdered the DAT on the 4th, but these occurrences are too few and far apart.
IMO your chances become extremely hindered once you take it 4/5 times and your not really improving from your previous first 3 attempts....
treat this test with respect, it can open all different doors for your future