Our FTC team (FIX IT 3491) has worked with Vuforia. Last season, we played around with some image processing. It had a basic purpose, but it was still difficult to complete. When we learned of Vuforia, we jumped at it. So far, we've tracked several objects (e.g. calculator, toothpaste) and, since we have a little experience with image processing in OpenCV, we've come to appreciate just how nice Vuforia is.
We've edited the code from the Vuforia sample app to work with the FTC code and extract the rotation/location of objects that the camera can see. We figured that, since we already did the work, there wasn't any reason for others to do it again (unless they're curious, of course). So we're posting a "Vuforia in FTC" tutorial on Youtube that describes the importing process and how to begin object tracking in the FTC app. For anyone interested, here's the link: Vuforia in FTC - YouTube. So far, there are two videos with a few more on the way.
From our experience so far, we love Vuforia. It's really easy to begin tracking objects and use them in your OpModes. We definitely recommend using this in the next season, even if it's only in your pit displays (although there are many uses on the field).
