There are only a very few appearance differences--but the method by which it calculates and displays the prices of items is drastically improved. (For those familiar with the MVC definition of software, the view and controller are unchanged, but the model is definitely improved.) Where it used to be static server-side HTML, it now dynamically calculates shipped price. The prices of all items and the shipping costs (of which there are really only two categories, to three regions of the world) are now located in a single HTML file.
Feel free to poke around ScopeRoller's website. I've tested it with Safari, Chrome, Firefox, and Internet Explorer 7, but let me know if you find anything that looks wrong or messed up with your favorite browser.