I looked at both this and Booxter before I decided to buy Booxter. It really did not come down to features, as they are similar, it came down to the interface. I really prefered the layout and look of Booxter. I think I mostly prefer it because it mimics the style of iPhoto and iTunes and has smart lists which is very important to me.

Both applications are great, really great, but if you like iPhoto and iTune's interface then you may prefer Booxter.