I have an EDTracker and love it. I've had it for 7 months. I can't imagine playing ED without it at this point. I use OpenTrack to add head tilt, since the EDTracker software doesn't have tilt.
Unfortunately, OpenTrack seems to suffer from drift and occasional head-freeze, so I have to Alt+Tab and turn it off and back on again, every 15 minutes or so. It's still worth the effort. I should probably check to see if a new version of OpenTrack is available.