Painting in Photoshop

I downloaded a trial version of CS5 and I wanted to try out the new painting feature.  You simply paint over what is already there and it acts just like real paint would.  This is a senior portrait that I did of Lindsey a couple months ago and it took me about six and a half hours to paint it.  I made sure to paint over EVERY pixel.  The before and after are both here for comparison.