Summary: This is my first GPS system so I did a lot of research online before I went ahead purchase it in March 2007. I wanted a large screen one and traffic system. 4500 seems to be the perfect match.
Pro: large screen, real-time traffic system saved me many times, and reasonable routing suggestions. I don't have the rerouting adaptation problem as the other reviewers and if I get into a side road, it'll recalculate immediately.