The goby eats Very well. He always is sifting through the sandbed almost every time I look at the tank. He loves frozen brine/mysis shrimp as well. He goes crazy for it. I feel bad when I feed pellets because he tried to eat it but it slips out his gills where the sand comes out lol. But the goby gets most of it's food from the sand bed. I like it because any food that is not eaten usually lays on the sand bed and breaks down the goby scoops it up if my shrimp don't get to it. At first, yes he made a mess because there was a lot of dust and just dirty sand because I had it up for a couple months and it was never turned over. After about 2 or 3 days there is no more mess. The most important thing is to make sure your rocks are steady. The goby will dig and take mouthfuls of sand close the the rocks and around the glass perimeter. If you put your rock in first, then the sand you'll be ok. I put the sand in first, then layed the rock and dug it in a little bit but this was before I realized and knew more about the hobby. The goby will dig a cave or two under your rock to sleep and rest in. This caused some of my rocks to topple down. Nothing was damaged - I just don't like the way it looks now since I had to do some rearranging. Sorry for the long drawn out response - I'm bored at work lol.