Benefits are simple, better breathing and the larger tank won't get clogged up as quickly, forcing excess oil through the induction side of the turbo.

Oil vapour can rapidly reduce the octane level of fuel by contamination of the combustion chamber. By diverting this vapour and allowing it to condense in an oil catch tank, you not only remove this vapour and unwanted crankcase pressures, but also help reduce the chance of piston detonation.