When I first got this project, I was hesitant. The goal was to port their old site (which was a mix of one Joomla install and several WordPress sites) into one consistent WordPress install; oh, and not lose money on the project. It turned out to be very difficult. One of the big learnings from this project was that your site will always be developed better if you get all the designs done before development starts. That said, it worked out in the end.
One of the hardest things to do was to keep the URLs the same on the new site. We had to do a bit of complex redirecting using built-in WordPress functionality but were able to make it happen.
Lastly, the custom breadcrumbs took a considerable amount of work, but as you can see, they work like a charm.
Live Project Link: http://www.upyourservice.com/