We used Java for the robot and LabVIEW for the dashboard. We had experience making LabVIEW dashboards and no experience with writing widgets for SmartDashboard, so when we decided we needed a display for the drivers we used the tools we knew. It was very effective and not difficult to implement.
An example of sending data from a Java robot to a LabVIEW dashboard is in our
2012 code. (The LabVIEW side isn't uploaded, but PM me if you'd like a look.) If you're interested in sending data back to the robot from LabVIEW, check out
this thread.