I had a previous one fail quite dramatically (open flame, hole melted in the side of the ballast housing), and reported it to Sylvania primarily to find out how to send it back to them for failure analysis. They sent me back a near-replacement ("warm white", but serviceable for outdoor use), but still didn't give me a way to send back the failed bulb back until I explicitly asked them about how to send it to them, "since I assume you'll be wanting to do a failure analysis."
So, a few weeks later, I get a note back from them saying, "We found that an internal component failed."
Well, DUH! I could have told YOU that without opening the housing.