Whilst I agree completely with what MFS and JT have said about the authenticity of the sim modelling, I too have tried the triple hydraulic failure in the sim and it is really quite flyable.
Airbus TPs who have flown our sim, and have had the chance to fly this in the a/c for real, said that the modelling is pretty good. There might be upfloat on the ailerons and spoilers with total hydraulic loss but it would depend on the failure mode and where the control surfaces were at the time of failure. From memory our sim gives aileron upfloat.
As W2P has said the 'Sioux City' scenario is a little more tricky but still flyable once the datums have been established.
The reality is that the redundancy built into the system is such that, while a triple hydraulic failure is of course possible, it is statistically very unlikely. The flight control computers all going off line at once ( or being unable to work due to the appropriate system loss) is also very unlikely and the a/c was always intended to be flown with rudder and stabiliser control available until a FCC was reset.
During very early flight test I understand that the a/c was indeed flown to landing on stabiliser and rudder alone, and while the aircraft hasn't read the FCOM, I still feel that any exposure to the worst case scenarios is of benefit and would at least give one a fighting chance of adopting the correct technique even if the numbers were slightly off.