That is not entirely correct, same angles keep the oscillation vibrations to a minimum and for joint longevity for the needles to circulate and pull in grease they need some angle on a DD, not race and performance vehicles.
If your entire driveline is straight then you have no loss thru angles and are perfect, and in the performance world will have no vibrations...
As rpm increases at the shaft YOU must run less angle so eventually at some point you will have to put the motor and trans at the same 0 degree as the shaft and diff.
If you have it already at 0 then your worst issue will be a joint that needs to be replaced at 10,000 miles rather than 40,000
