swooshing might be caused by the angle of your attack.

I always attack at an angle, which makes a swooshing/scratching noise. I don't really mind it but some people told me about it.

Try to pick flat without any angle. Take The Jonezter (another host) for instance he was the first one to point that out for me. He picks totally flat, and his notes comes out very clean at high speed.

My picking is getting better but changing a simple thing as angle picking whne you've been playing as long as I do, it's not easy :)