The main advantages of IT system are the followings;
It improves the energy availability: this is interesting for applications where a loss of electricity supply can cause a risk to people (in hospitals for example), or a financial risk (for some process in industry).
IT can also eliminate the risks of fire or explosions in case of insulation fault, as the faulty current is very low.
IT will increase electrical device life time, as faulty current is low, it causes less stress on the equipement.
Finally, it is possible to do preventive maintenance on the IT installation, through the permanent insulation monitor device. We can detect insulation drops before they become insulation faults.