For a while, our feeder had been using the thermoformed polycarbonate shell that we made many months ago. However, for worlds, we have just had an extruded acrylic shell custom made. It is cleaner looking and is one piece, with no breaks in it.
Update: Unfortunately, it turns out that the new feeder is not as tall as the old, thermoformed polycarbonate one was, so blocks very easily get stuck on their way in. So we've switched back to the old one, but mounted slightly differently to improve performance.
Comparison of old vs. new: