If I understand correctly then it would be called anti-dive if executed correctly and you have front brakes.
The advantage is that when the brakes are applied they try to rotate the spindle which in turn causes the front end to try to lift, counteracting the dive as the weight is transfered to the front of the car.
The disadvantage is that your caster angle changes as the suspension travels. Not a big deal on a road car with a couple inches of travel but with long travel if you have enough angle built in to cause the anti-dive then at the ends of travel you will have a significant change in caster angle.
Eta: I am referring to the A-arm inner mounts not being parallel when looking from the side of the car.
If you are referring to them not being parallel when looking from the top of the car then that is a totally different animal.
