Which is better for applying liquid foundation -- synthetic or natural brush?

use your fingers or a sponge. but if you must, use a natural brush :]Which is better for applying liquid foundation -- synthetic or natural brush?
I use a synthetic brush and it works well for me, but I've never used a natural brush so I dont know which is really better.Which is better for applying liquid foundation -- synthetic or natural brush?
I've always heard that your fingers is best because the heat in your hands helps spread the foundation evenly.