While the argument at the moment is that a price level target allows the central bank to let the economy grow more strongly after a period of unexpectedly low inflation, again I do not think that practically this will deliver better outcomes than a flexible inflation target. That is an empirical question in the end which is worth testing.
The appropriate level of the inflation target is currently being debated in some parts of the world, including the US. The argument for a higher target rate of inflation is that it might reduce the risk of hitting the zero lower bound because a higher inflation rate would result in a higher nominal interest rate structure.