they regulate the air fuel mixture for when the pressure cant be adjusted, it is set to around 3 bar but at idle drops this by approx .5 bar so when on full ecceleration it raises the fuel pressure, making it run lean. the power boost valve allows this toi be regualted as it can adjust the the mixture etc.
thus better with high increases with CAI's and forced inductions etc. mods that would alter the air fuel mixture. (which u dont have)
so in lamens terms. it reduces the flat spots and the bad idling that occurs when the air fuel mixture is altered, and since the regulator is non adjustable this is were the power boost valve comes into it!
happy now biatcha