What Is The Difference Between Sony Vegas Pro 9 & Adobe Audition 3?

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I was going to buy sony vegas pro because I need a software that I can record and edit my songs. I currently use audacity but it doesn't give enough options and not enough tools to work with. I recently heard that sony vegas pro 9 could help me produce and edit tracks but I then heard a lot of stuff about video editing. After that I heard about adobe audition could help me. I just wanna know the difference between softwares and see which one can give me the better results. Thanks