So you trade GoxBTC for GoxUSD? How is that going to help in a bankruptcy?
Well, I think that "he owes me 10,000 dollars" sounds more serious to a prosecutor or judge than "he owes me 50 bitcoins".
On the other hand, once a MtGOX client sells his 1 goxBTC for 200 goxUSD, he forfeits his right to the 1 realBTC that he was owed before, and can sue them for only 200 realUSD.