Well, I just got my DVX100a yesterday and I filmed a little demonstration of how the shutter speed looks at 1/250 in 24p mode. It looks a lot like the "saving private ryan" effect that I have been attempting. The lighting in the house is low already and by speeding up the shutter... it is even lower. It is insane how much light you must have for a fast shutter speed. Anyway, the video can be seen here:
http://www.pizcofilms.com/videofiles/shuttertest.mov
http://www.pizcofilms.com/videofiles/shuttertest.mov