I had a diamond goby before - very active, fun to watch. Downside was he definitely made a MESS of my sand bed, burying everything (rock pieces, corals), making mountains everywhere and one day he decided he was very determined to squeeze his way out of the ONLY 1 inch square hole in the mesh-top which covers my tank, and he was successful. RIP goby
(they are notorious for jumping if you didn't already know, but you probably did lol. 99% of the diamond goby deaths are from suicide jumping).