Updated review...After a rough start, the app is working properly. We use Product Options by Bold and the two apps were having some issues with each other. After several patches/updates, things appear to be working properly. Customers see the accurate rates they need. Thanks to Corbin for all his help.
UPDATED REVIEW (Originally 1/5): Initial setup was a large hassle due in part to unreliable communication with customer service drawn out over the course of three weeks. However, once you get past the setup, the shipping interface is unbelievably simple and the real-time updates make it about as easy as humanly possible for your customers. So far, worth the trouble it takes to get it off the ground.
Easy to setup and customers get a pretty accurate quote.